wlan :Fix issues observed in static code analysis.

Fixes  the possible NULL pointer derefernce and buffer overflows
observed in static code analysis.

Change-Id: Ia120158508f914f2f7af341d430b23e26817d552
CRs-Fixed: 642599
wlan: Pass current band information to reg notifiers.

There is a regression in wlan_hdd_linux_reg_notifier; where
band capability should be taken from GUI only.

CRs-Fixed: 650857
Change-Id: I46c34d2cfc6e5126847e9120522cd6874f7f840d
wlan: Fix potential stack corruption

Type casting a 16-bit structure pointer by 32-bit integer pointer and
then dereference/assigning value may casue memory corruption. Fix it
by directly using a 32-bit integer pointer and assigning the value of
16-bit structure to it.

Change-Id: I507cf7da42e2bcdedb309e7ea5e771721f0747ab
CRs-fixed: 654158
Wlan : Revision 3.2.3.306

Revision 3.2.3.306

Change-Id: I455248ffc6e7fd88cf0ed664d6f3f649def8289c