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-r4k.c

@@ -108,16 +108,8 @@ EXPORT_SYMBOL(local_flush_tlb_all);
    these entries, we just bump the asid. */
 void local_flush_tlb_mm(struct mm_struct *mm)
 {
-	int cpu;
-
 	preempt_disable();
-
-	cpu = smp_processor_id();
-
-	if (cpu_context(cpu, mm) != 0) {
-		drop_mmu_context(mm);
-	}
-
+	drop_mmu_context(mm);
 	preempt_enable();
 }