qcacmn: wmi: 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 wmi replace any such comparisons with logical
operations performed on the pointer itself.

Change-Id: Ida6b1b32330d97392bd879f84929782a64f4fc85
CRs-Fixed: 2418250
3 files changed