ALSA: Replace the magic number 44 with const

The char arrays with size 44 are for the name string of
snd_ctl_elem_id.  Define the constant and replace the raw numbers with
it for clarifying better.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_jack.c b/sound/pci/hda/hda_jack.c
index 9e0a952..3fd2973 100644
--- a/sound/pci/hda/hda_jack.c
+++ b/sound/pci/hda/hda_jack.c
@@ -398,7 +398,7 @@
 			 const char *base_name)
 {
 	unsigned int def_conf, conn;
-	char name[44];
+	char name[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
 	int idx, err;
 	bool phantom_jack;