qcacmn: Fix maybe-uninitialized compilation failure

'dest_desc' may be used uninitialized in function
ce_recv_buf_enqueue_srng/hif_record_ce_srng_desc_event, when
Werror=maybe-uninitialized enabled.

Change-Id: I13281d74bcfff5eb7474af729fd70d90c024ee75
CRs-Fixed: 2519213

hif/src/ce/ce_service_srng.c

@@ -340,8 +340,10 @@ ce_recv_buf_enqueue_srng(struct CE_handle *copyeng,
 								write_index);
 			status = QDF_STATUS_SUCCESS;
 		}
-	} else
+	} else {
+		dest_desc = NULL;
 		status = QDF_STATUS_E_FAILURE;
+	}
 
 	dest_ring->write_index = write_index;
 	hal_srng_access_end(scn->hal_soc, dest_ring->srng_ctx);