m68k/macboing: Fix missed timer callback assignment

This fixes a missed function prototype callback from the timer conversions.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20171123221902.GA75727@beast

arch/m68k/mac/macboing.c

@@ -50,7 +50,7 @@ static unsigned long mac_bell_phasepersample;
 static void mac_init_asc( void );
 static void mac_nosound(struct timer_list *);
 static void mac_quadra_start_bell( unsigned int, unsigned int, unsigned int );
-static void mac_quadra_ring_bell( unsigned long );
+static void mac_quadra_ring_bell(struct timer_list *);
 static void mac_av_start_bell( unsigned int, unsigned int, unsigned int );
 static void ( *mac_special_bell )( unsigned int, unsigned int, unsigned int );
 
@@ -270,7 +270,7 @@ static void mac_quadra_start_bell( unsigned int freq, unsigned int length, unsig
  * already load the wave table, or at least call this one...
  * This piece keeps reloading the wave table until done.
  */
-static void mac_quadra_ring_bell( unsigned long ignored )
+static void mac_quadra_ring_bell(struct timer_list *unused)
 {
 	int	i, count = mac_asc_samplespersec / HZ;
 	unsigned long flags;