cpumask: use mm_cpumask() wrapper: m32r

Makes code futureproof against the impending change to mm->cpu_vm_mask.

It's also a chance to use the new cpumask_ ops which take a pointer
(the older ones are deprecated, but there's no hurry for arch code).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Hirokazu Takata <takata@linux-m32r.org> (fixes)
diff --git a/arch/m32r/include/asm/mmu_context.h b/arch/m32r/include/asm/mmu_context.h
index 91909e5dd..a70a3df 100644
--- a/arch/m32r/include/asm/mmu_context.h
+++ b/arch/m32r/include/asm/mmu_context.h
@@ -127,7 +127,7 @@
 
 	if (prev != next) {
 #ifdef CONFIG_SMP
-		cpu_set(cpu, next->cpu_vm_mask);
+		cpumask_set_cpu(cpu, mm_cpumask(next));
 #endif /* CONFIG_SMP */
 		/* Set MPTB = next->pgd */
 		*(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
@@ -135,7 +135,7 @@
 	}
 #ifdef CONFIG_SMP
 	else
-		if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
+		if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
 			activate_context(next);
 #endif /* CONFIG_SMP */
 }