qcacld-3.0: Check adapter is not NULL when receiving IPA_RECEIVE event

Check adapter is not NULL when receiving IPA_RECEIVE event,
to avoid null dereference when the interface is already cleaned up.

Change-Id: Ic9240811f42edd4f495cb4eabe1268d24851d6d9
CRs-Fixed: 2001132
diff --git a/core/hdd/src/wlan_hdd_ipa.c b/core/hdd/src/wlan_hdd_ipa.c
index f90b87e..ba3ed33 100644
--- a/core/hdd/src/wlan_hdd_ipa.c
+++ b/core/hdd/src/wlan_hdd_ipa.c
@@ -4303,6 +4303,13 @@
 
 		iface_context = &hdd_ipa->iface_context[iface_id];
 		adapter = iface_context->adapter;
+		if (!adapter) {
+			HDD_IPA_LOG(QDF_TRACE_LEVEL_ERROR,
+				    "IPA_RECEIVE: Adapter is NULL");
+			HDD_IPA_INCREASE_INTERNAL_DROP_COUNT(hdd_ipa);
+			kfree_skb(skb);
+			return;
+		}
 
 		HDD_IPA_DBG_DUMP(QDF_TRACE_LEVEL_DEBUG,
 				"w2i -- skb",