MIPS: mm: Consolidate drop_mmu_context() has-ASID checks

If an mm does not have an ASID on the local CPU then drop_mmu_context()
is always redundant, since there's no context to "drop". Various callers
of drop_mmu_context() check whether the mm has been allocated an ASID
before making the call. Move that check into drop_mmu_context() and
remove it from callers to simplify them.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

arch/mips/mm/tlb-r8k.c

@@ -52,10 +52,7 @@ void local_flush_tlb_all(void)
 
 void local_flush_tlb_mm(struct mm_struct *mm)
 {
-	int cpu = smp_processor_id();
-
-	if (cpu_context(cpu, mm) != 0)
-		drop_mmu_context(mm);
+	drop_mmu_context(mm);
 }
 
 void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,