Fixes for midi input

- Fix buffer overflow in midi input messages
- Detect sysex messages by starting byte instead of length

src/include/86box/snd_sb_dsp.h

@@ -102,7 +102,7 @@ typedef struct sb_dsp_t
 } sb_dsp_t;
 
 
-void sb_dsp_input_msg(void *p, uint8_t *msg);
+void sb_dsp_input_msg(void *p, uint8_t *msg, uint32_t len);
 
 int sb_dsp_input_sysex(void *p, uint8_t *buffer, uint32_t len, int abort);