staging: wlan-ng: remove extra parentheses

Removes extra parentheses around function arguments. Issue
detected and resolved using the following coccinelle script:

@@
expression e;
identifier f;
@@

f(...,
-(
e
-)
,...)

Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>