[ALSA] sound/core/control.c: remove dead code

This patch removes some obviously dead code spotted by the Coverity
checker.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/core/control.c

@@ -1275,7 +1275,7 @@ static ssize_t snd_ctl_read(struct file *file, char __user *buffer,
 			schedule();
 			remove_wait_queue(&ctl->change_sleep, &wait);
 			if (signal_pending(current))
-				return result > 0 ? result : -ERESTARTSYS;
+				return -ERESTARTSYS;
 			spin_lock_irq(&ctl->read_lock);
 		}
 		kev = snd_kctl_event(ctl->events.next);