[ALSA] insert set_current_state() before schedule_timeout()

GUS Library
Insert set_current_state() before schedule_timeout(). Without the
insertion, schedule_timeout() returns immediately.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/gus/gus_pcm.c

@@ -333,6 +333,7 @@ static int snd_gf1_pcm_poke_block(snd_gus_card_t *gus, unsigned char *buf,
 			}
 		}
 		if (count > 0 && !in_interrupt()) {
+			set_current_state(TASK_INTERRUPTIBLE);
 			schedule_timeout(1);
 			if (signal_pending(current))
 				return -EAGAIN;