wil6210: fix protection of wil->scan_request

Currently the places that check wil->scan_request and
call cfg80211_scan_done are not consistently protected,
so there is a risk that cfg80211_scan_done will be called
with NULL scan_request, causing a kernel crash.
Fix this by using p2p_wdev_mutex in few other places
that access scan_request. This makes sense since
scan_request may point to p2p_wdev, and it is not worth
the extra complexity of adding a new mutex.

Signed-off-by: Lior David <qca_liord@qca.qualcomm.com>
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit 5ffae43208ec160e584117fabee2cddc5ad0e39a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


CRs-Fixed: 1063261
Change-Id: Ibc1e6dc2994268a60384b7d9bd459abc3791a0c4
Signed-off-by: Maya Erez <merez@codeaurora.org>