ALSA: seq: add error check in snd_seq_system_client_init()

Static checkers complain that snd_seq_create_kernel_client() can return
-EBUSY here so we need to have some error handling.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/seq/seq_system.c

@@ -134,6 +134,10 @@ int __init snd_seq_system_client_init(void)
 
 	/* register client */
 	sysclient = snd_seq_create_kernel_client(NULL, 0, "System");
+	if (sysclient < 0) {
+		kfree(port);
+		return sysclient;
+	}
 
 	/* register timer */
 	strcpy(port->name, "Timer");