qcacld-3.0: Fix dead loop in hdd_get_sap_operating_channel
qcacld-2.0 to qcacld-3.0 propagation
In the while loop of hdd_get_sap_operating_channel,
sap_operating_band should be revalued, otherwise it causes
dead loop.
Change-Id: I9cb1ae738066567d032f99621ffe04d3beb74b8c
CRs-Fixed: 1094604