x86/mm: Clean up inconsistencies when flushing TLB ranges

NR_TLB_LOCAL_FLUSH_ALL is not always accounted for correctly and
the comparison with total_vm is done before taking
tlb_flushall_shift into account.  Clean it up.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Tested-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Alex Shi <alex.shi@linaro.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Link: http://lkml.kernel.org/n/tip-Iz5gcahrgskIldvukulzi0hh@git.kernel.org


Signed-off-by: Ingo Molnar <mingo@kernel.org>