[ALSA] Fix a typo in echoaudio/midi.c

Fixed a typo in echoaudio/midi.c.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

sound/pci/echoaudio/midi.c

@@ -44,7 +44,7 @@ static int enable_midi_input(struct echoaudio *chip, char enable)
 	if (enable) {
 		chip->mtc_state = MIDI_IN_STATE_NORMAL;
 		chip->comm_page->flags |=
-			_constant_cpu_to_le32(DSP_FLAG_MIDI_INPUT);
+			__constant_cpu_to_le32(DSP_FLAG_MIDI_INPUT);
 	} else
 		chip->comm_page->flags &=
 			~__constant_cpu_to_le32(DSP_FLAG_MIDI_INPUT);