rtl8188eu: Fix smatch warning in core/rtw_br_ext.c

Smatch reports the following warning:
  CHECK   /home/finger/rtl8188eu/core/rtw_br_ext.c
/home/finger/rtl8188eu/core/rtw_br_ext.c:693 nat25_db_handle() info: ignoring unreachable code.

Remove an entra return statement.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Fix smatch warnings in core/rtw_cmd.c

Smatch reports the following warnings:
  CHECK   /home/finger/rtl8188eu/core/rtw_cmd.c
/home/finger/rtl8188eu/core/rtw_cmd.c:385 rtw_cmd_thread() error: buffer overflow 'wlancmds' 63 <= 63
/home/finger/rtl8188eu/core/rtw_cmd.c:403 rtw_cmd_thread() error: buffer overflow 'rtw_cmd_callback' 63 <= 63

These are caused by an off-by-one error using <= rather than <.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Fix smatch warnings in core/rtw_efuse.c

Smatch reports the following warnings:

  CHECK   /home/finger/rtl8188eu/core/rtw_efuse.c
/home/finger/rtl8188eu/core/rtw_efuse.c:646 rtw_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
/home/finger/rtl8188eu/core/rtw_efuse.c:655 rtw_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
/home/finger/rtl8188eu/core/rtw_efuse.c:738 rtw_BT_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8
/home/finger/rtl8188eu/core/rtw_efuse.c:747 rtw_BT_efuse_map_write() error: buffer overflow 'newdata' 8 <= 8

These are due to an off-by-one error in an array size.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Fix smatch warning in core/rtw_ieee80211.c

Smatch reports the following warning:
  CHECK   /home/finger/rtl8188eu/core/rtw_ieee80211.c
/home/finger/rtl8188eu/core/rtw_ieee80211.c:161 rtw_set_ie() info: ignoring unreachable code.

This warning is caused by a _func_exit_ macro placed after the return.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
rtl8188eu: Fix smatch problems in core/rtw_ioctl_set.c

Smatch reports the following problems:
  CHECK   /home/finger/rtl8188eu/core/rtw_ioctl_set.c
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:593 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:595 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKeylen' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:599 rtw_set_802_11_add_wep() error: buffer overflow 'psecuritypriv->dot11DefKey' 4 <= 4
/home/finger/rtl8188eu/core/rtw_ioctl_set.c:745 rtw_set_802_11_add_key() warn: was && intended here instead of ||?

The buffer overflow messages are due to an off-by-one problem. An if test skips code
for a value > 4. It should be >= 4.

The warning for a suspect logical operator was correct. With a logical or in the statement,
it made no sense.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>