MIPS: Remove incorrect NULL check in local_flush_tlb_page()

We check that the struct vm_area_struct pointer vma is NULL and then
dereference it a few lines below. The intent was to make sure vma is
not NULL but this is not necessary since the bug pre-dates GIT history
and seem to never have caused a problem. The tlb-4k and tlb-8k versions
of local_flush_tlb_page() don't bother checking if vma is NULL, also
vma is dereferenced before being passed to local_flush_tlb_page(),
thus it is safe to remove this NULL check.

Signed-off-by: Emil Goode <[e-mail]>
Reviewed-by: Jonas Gorski <[e-mail]>
Acked-by: Maciej W. Rozycki <[e-mail]>
Cc: Paul Gortmaker <[e-mail]>
Cc: John Crispin <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/7264/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/mm/tlb-r3k.c

···
 {
 	int cpu = smp_processor_id();
 
-	if (!vma || cpu_context(cpu, vma->vm_mm) != 0) {
+	if (cpu_context(cpu, vma->vm_mm) != 0) {
 		unsigned long flags;
 		int oldpid, newpid, idx;