[MIPS] Oprofile: Fix rm9000 performance counter handler

The new type of irq handler remove a parameter (struct pt_regs *),but
someone forgot to supply it.
Signed-off-by: NDajie Tan <jiankemeng@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/oprofile/op_model_rm9000.c

@@ -83,6 +83,7 @@ static void rm9000_cpu_stop(void *args)
 static irqreturn_t rm9000_perfcount_handler(int irq, void * dev_id)
 {
 	unsigned int control = read_c0_perfcontrol();
+	struct pt_regs *regs = get_irq_regs();
 	uint32_t counter1, counter2;
 	uint64_t counters;