ALSA: rawmidi: (cosmetic) align function parameters

fix cppcheck:

sound/core/rawmidi.c:1711:49: style:inconclusive: Function
'snd_rawmidi_free' argument 1 names different: declaration 'rawmidi'
definition 'rmidi'. [funcArgNamesDifferent]
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200902212133.30964-16-pierre-louis.bossart@linux.intel.comSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/rawmidi.c

@@ -35,7 +35,7 @@ module_param_array(amidi_map, int, NULL, 0444);
 MODULE_PARM_DESC(amidi_map, "Raw MIDI device number assigned to 2nd OSS device.");
 #endif /* CONFIG_SND_OSSEMUL */
 
-static int snd_rawmidi_free(struct snd_rawmidi *rawmidi);
+static int snd_rawmidi_free(struct snd_rawmidi *rmidi);
 static int snd_rawmidi_dev_free(struct snd_device *device);
 static int snd_rawmidi_dev_register(struct snd_device *device);
 static int snd_rawmidi_dev_disconnect(struct snd_device *device);