wlan: Fix for crash during wlan unloading.

Scan request can receive during unloading in progress.
So added check before proceesing scan request whether
unloading in progress or not.

Change-Id: I13f8efb26e0206007ee8c98943238e8ed8e4c5f5
CRs-Fixed: 393218
diff --git a/CORE/HDD/src/wlan_hdd_cfg80211.c b/CORE/HDD/src/wlan_hdd_cfg80211.c
index 5cd74ec..ae30285 100644
--- a/CORE/HDD/src/wlan_hdd_cfg80211.c
+++ b/CORE/HDD/src/wlan_hdd_cfg80211.c
@@ -3600,6 +3600,12 @@
         return -EAGAIN;
     }
 
+    if ((WLAN_HDD_GET_CTX(pAdapter))->isLoadUnloadInProgress)
+    {
+        VOS_TRACE(VOS_MODULE_ID_HDD, VOS_TRACE_LEVEL_FATAL,
+                  "%s:Unloading/Loading in Progress. Ignore!!!", __func__);
+        return -EAGAIN;
+    }
     //Don't Allow Scan and return busy if Remain On 
     //Channel and action frame is pending
     //Otherwise Cancel Remain On Channel and allow Scan