mm: drop duplicated words in <linux/mm.h>

Drop the doubled words "to" and "the".

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Link: http://lkml.kernel.org/r/d9fae8d6-0d60-4d52-9385-3199ee98de49@infradead.org


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>