qcacld-3.0: Rename pMac in sme_api.c

Per the Linux coding style "mixed-case names are frowned upon" and
"so-called Hungarian notation [...] is brain damaged." One identifier
used extensively throughout the driver that violates both of these
tenants is "pMac." In order to be compliant with the Linux coding
style there is a campaign to rename all instances of this identifier.

For this change rename all instances of "pMac" to "mac" in:
sme_api.c

Change-Id: If45f33b93230d1085ee1a3c4dbf35e1f4bfcab27
CRs-Fixed: 2356102