[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: Dajie Tan <[e-mail]>
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/oprofile/op_model_rm9000.c

···
 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;