ALSA: seq: More constifications

Apply const prefix to the remaining sequencer code: the static tables
for MIDI macros, RPN/NRPN, and some strings.

Just for minor optimization and no functional changes.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Takashi Iwai <[e-mail]>

sound/core/seq/oss/seq_oss_init.c

···
 	return bool ? "enabled" : "disabled";
 }
 
-static char *
+static const char *
 filemode_str(int val)
 {
-	static char *str[] = {
+	static const char * const str[] = {
 		"none", "read", "write", "read/write",
 	};
 	return str[val & SNDRV_SEQ_OSS_FILE_ACMODE];

sound/core/seq/seq_midi_emul.c

···
       struct snd_midi_channel_set *chset)
 {
 	/* GM on */
-	static unsigned char gm_on_macro[] = {
+	static const unsigned char gm_on_macro[] = {
 		0x7e,0x7f,0x09,0x01,
 	};
 	/* XG on */
-	static unsigned char xg_on_macro[] = {
+	static const unsigned char xg_on_macro[] = {
 		0x43,0x10,0x4c,0x00,0x00,0x7e,0x00,
 	};
 	/* GS prefix
···
 	 * chorus mode: XX=0x01, YY=0x38, ZZ=0-7
 	 * master vol:  XX=0x00, YY=0x04, ZZ=0-127
 	 */
-	static unsigned char gs_pfx_macro[] = {
+	static const unsigned char gs_pfx_macro[] = {
 		0x41,0x10,0x42,0x12,0x40,/*XX,YY,ZZ*/
 	};
 

sound/core/seq/seq_midi_event.c

···
 			     int count, struct snd_seq_event *ev)
 {
 	unsigned char cmd;
-	char *cbytes;
-	static char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
+	const char *cbytes;
+	static const char cbytes_nrpn[4] = { MIDI_CTL_NONREG_PARM_NUM_MSB,
 				       MIDI_CTL_NONREG_PARM_NUM_LSB,
 				       MIDI_CTL_MSB_DATA_ENTRY,
 				       MIDI_CTL_LSB_DATA_ENTRY };
-	static char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,
+	static const char cbytes_rpn[4] =  { MIDI_CTL_REGIST_PARM_NUM_MSB,
 				       MIDI_CTL_REGIST_PARM_NUM_LSB,
 				       MIDI_CTL_MSB_DATA_ENTRY,
 				       MIDI_CTL_LSB_DATA_ENTRY };