qcacld-3.0: wma: Replace explicit comparison to NULL

Per the Linux Kernel coding style, as enforced by the kernel
checkpatch script, pointers should not be explicitly compared to
NULL. Therefore within wma replace any such comparisons with logical
operations performed on the pointer itself.

Change-Id: I2b4125bc4ec229fbe466e6ce0ca4c3191f6cae59
CRs-Fixed: 2418387
10 files changed