qcacld-3.0: Add fallthrough comment in __iw_set_host_offload()
In __iw_set_host_offload() there is a switch statement where the logic
for case WLAN_OFFLOAD_ARP_AND_BC_FILTER_ENABLE falls through to the
next case. Add a fallthrough comment to explicitly document that this
is the desired behavior as opposed to a missing break statement.
Change-Id: I9a7d84841d9d059e822ee15ee482111ca9d87caf
CRs-Fixed: 2233178