ALSA: opl3: Kill unused set_fs()

snd_enter_user() and snd_leave_user() that call set_fs() are the dead
code in opl3 driver.  Let's rip them off.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/opl3/opl3_oss.c

@@ -27,20 +27,6 @@ static int snd_opl3_ioctl_seq_oss(struct snd_seq_oss_arg *arg, unsigned int cmd,
 static int snd_opl3_load_patch_seq_oss(struct snd_seq_oss_arg *arg, int format, const char __user *buf, int offs, int count);
 static int snd_opl3_reset_seq_oss(struct snd_seq_oss_arg *arg);
 
-/* */
-
-static inline mm_segment_t snd_enter_user(void)
-{
-	mm_segment_t fs = get_fs();
-	set_fs(get_ds());
-	return fs;
-}
-
-static inline void snd_leave_user(mm_segment_t fs)
-{
-	set_fs(fs);
-}
-
 /* operators */
 
 extern struct snd_midi_op opl3_ops;