wlan: Avoid kernel panic during regionNumber access

Decrement regionNumber value only when regionNumber is greater then zero.
Protect regionNumber value with lock before accessing/changing.

CRs-fixed: 491383
Change-Id: Ib54a0007c2df1ad743bb16a7798498be71f52680
1 file changed
tree: 6dc10a1458d40b47a9e7e970087b098f16b86c92
  1. CORE/
  2. firmware_bin/
  3. riva/
  4. Android.mk
  5. Kbuild
  6. Kconfig