qcacld-3.0: Avoid user after free in wma_delete_sta

If wma_send_msg_high_priority failed to send msg, msg body is freed,
can't access later.
Move wma_delete_sta_req_sta_mode and log to avoid use after free.
Duplicate MLME_IS_ROAM_SYNCH_IN_PROGRESS is called in 3 functions in
same stack, clean up it.

Change-Id: I28b7cc9f12902aefa37bf1345c94ec6f0b581297
CRs-Fixed: 2748407