ALSA: hda - Fix initialization of spec->automute_lines in patch_realtek.c

spec->automute_lines shouldn't be set unless the line-detection is
available.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 473ddc7..1f00cdb 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -1584,7 +1584,7 @@
 					AC_USRSP_EN | ALC880_FRONT_EVENT);
 			spec->detect_line = 1;
 		}
-		spec->automute_lines = 1;
+		spec->automute_lines = spec->detect_line;
 	}
 
 	if (spec->automute) {