net: iosm: remove an unnecessary NULL check

The address of &ipc_mux->ul_adb can't be NULL because it points to the
middle of a non-NULL struct.

Fixes: 9413491e ("net: iosm: encode or decode datagram")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NM Chetan Kumar <m.chetan.kumar@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/wwan/iosm/iosm_ipc_mux_codec.c

@@ -477,7 +477,7 @@ static void ipc_mux_ul_adgh_finish(struct iosm_mux *ipc_mux)
 	long long bytes;
 	char *str;
 
-	if (!ul_adb || !ul_adb->dest_skb) {
+	if (!ul_adb->dest_skb) {
 		dev_err(ipc_mux->dev, "no dest skb");
 		return;
 	}