[ALSA] Fix seq_clientmgr dereferences before NULL check

Modules: ALSA sequencer

cptr->pool must be non-NULL there, so just the if (cptr->pool) is
superfluous. Thanks Takashi.
Signed-off-by: NEugene Teo <eugene.teo@eugeneteo.net>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

sound/core/seq/seq_clientmgr.c

@@ -1866,8 +1866,7 @@ static int snd_seq_ioctl_get_client_pool(struct snd_seq_client *client,
 	info.output_pool = cptr->pool->size;
 	info.output_room = cptr->pool->room;
 	info.output_free = info.output_pool;
-	if (cptr->pool)
-		info.output_free = snd_seq_unused_cells(cptr->pool);
+	info.output_free = snd_seq_unused_cells(cptr->pool);
 	if (cptr->type == USER_CLIENT) {
 		info.input_pool = cptr->data.user.fifo_pool_size;
 		info.input_free = info.input_pool;