wifi_statistics: remove unused lock

the lock member in the ws_sta struct is declared and
initialised, but never used.

Remove it from the structure.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: shorten copyright line

To make the copyright line shorter than 80 chars, the latter
has been slightly changed

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: checkpatch cleanup

- shorten long line
- remove trailing whitespace
- use seq_puts when possible

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: use kstrtoul instead of strict_stroul

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
[siwu@hrz.tu-chemnitz.de: fix commit message]
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
wifi_statistics: fops variables has to be const

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: debugfs_remove_recursive does not need NULL check

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: shorten module defines

WIFI_STATISTICS* define have been renamed to WIFI_STATS*

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: add lock comment

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
wifi_statistics: make the code checkpatch strict clean

Remove spaces in cast, blank lines before closing brackets
and correctly align parenthesis

Signed-off-by: Antonio Quartulli <ordex@autistici.org>