ALSA: ctxfi: Swapped SURROUND-SIDE mute

On Soundblaster X-FI Titenium with emu20k2 the SIDE and SURROUND mute
functions are swapped.
It was checked with 'speaker-test -c 8 -s 3' and (un)mute surround or
'speaker-test -c 8 -s 7' and (un)mute side. The volume seems not
to be affected and works as expected.
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/ctxfi/ctatc.c

@@ -1037,7 +1037,7 @@ static int atc_line_front_unmute(struct ct_atc *atc, unsigned char state)
 
 static int atc_line_surround_unmute(struct ct_atc *atc, unsigned char state)
 {
-	return atc_daio_unmute(atc, state, LINEO4);
+	return atc_daio_unmute(atc, state, LINEO2);
 }
 
 static int atc_line_clfe_unmute(struct ct_atc *atc, unsigned char state)
@@ -1047,7 +1047,7 @@ static int atc_line_clfe_unmute(struct ct_atc *atc, unsigned char state)
 
 static int atc_line_rear_unmute(struct ct_atc *atc, unsigned char state)
 {
-	return atc_daio_unmute(atc, state, LINEO2);
+	return atc_daio_unmute(atc, state, LINEO4);
 }
 
 static int atc_line_in_unmute(struct ct_atc *atc, unsigned char state)