ALSA: sb: Delete an unnecessary check before the function call "snd_emux_free"

The snd_emux_free() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/sb/emu8000_synth.c

@@ -103,7 +103,6 @@ static int snd_emu8000_delete_device(struct snd_seq_device *dev)
 	hw = dev->driver_data;
 	if (hw->pcm)
 		snd_device_free(dev->card, hw->pcm);
-	if (hw->emu)
 	snd_emux_free(hw->emu);
 	snd_util_memhdr_free(hw->memhdr);
 	hw->emu = NULL;