rtl8188eu: Fix smatch warning in os_dep/usb_intf.c

iSmatch shows the following warning:
  CHECK   /home/finger/rtl8188eu/os_dep/usb_intf.c
/home/finger/rtl8188eu/os_dep/usb_intf.c:720 rtw_resume_process() error: potentially dereferencing uninitialized 'pwrpriv'.

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

Smatch shows the following warning:
  CHECK   /home/finger/rtl8188eu/os_dep/recv_linux.c
/home/finger/rtl8188eu/os_dep/recv_linux.c:236 rtw_recv_indicatepkt() warn: variable dereferenced before check 'precv_frame' (see line 142)

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

Smatch shows the following warning:
  CHECK   /home/finger/rtl8188eu/os_dep/osdep_service.c
/home/finger/rtl8188eu/os_dep/osdep_service.c:670 rtw_change_ifname() warn: variable dereferenced before check 'padapter' (see line 666)

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

Smatch reports the following warnings:
  CHECK   /home/finger/rtl8188eu/os_dep/ioctl_linux.c
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:991 rtw_wx_set_pmkid() warn: add some parenthesis here?
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:1092 rtw_wx_get_range() warn: assigning (-78) to unsigned variable 'range->avg_qual.level'
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:2742 rtw_get_ap_info() warn: add some parenthesis here?
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:4225 rtw_rereg_nd_name() warn: add some parenthesis here?
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:4234 rtw_rereg_nd_name() warn: add some parenthesis here?
/home/finger/rtl8188eu/os_dep/ioctl_linux.c:5072 set_group_key() warn: missing break? reassigning 'keylen'

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

Smatch shows the following:
  CHECK   /home/finger/rtl8188eu/hal/usb_ops_linux.c
/home/finger/rtl8188eu/hal/usb_ops_linux.c:630 usb_read_port() warn: variable dereferenced before check 'precvbuf' (see line 627)

The code is refactored.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Merge branch 'next' of https://github.com/Noltari/rtl8188eu
Move vars from rtw_recv.h to rtw_recv.c in order to prevent unused vars warnings when including rtw_recv.h.
Note that SNAP_ETH_TYPE_APPLETALK_DDP, SNAP_ETH_TYPE_TDLS, SNAP_HDR_APPLETALK_DDP, oui_8021h and oui_rfc1042 are still unused and can be commented out.