ALSA: jack: Check the return value of kstrdup()

kstrdup() can return NULL, it is better to check the return value of it.
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/tencent_094816F3522E0DC704056C789352EBBF0606@qq.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/jack.c

@@ -509,6 +509,10 @@ int snd_jack_new(struct snd_card *card, const char *id, int type,
 		return -ENOMEM;
 
 	jack->id = kstrdup(id, GFP_KERNEL);
+	if (jack->id == NULL) {
+		kfree(jack);
+		return -ENOMEM;
+	}
 
 	/* don't creat input device for phantom jack */
 	if (!phantom_jack) {