linux/sched/mm.h: drop duplicated words in comments

Drop doubled words "to" and "that".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/927ea8d8-3f6c-9b65-4c2b-63ab4bd59ef1@infradead.org

include/linux/sched/mm.h

@@ -23,7 +23,7 @@ extern struct mm_struct *mm_alloc(void);
  * will still exist later on and mmget_not_zero() has to be used before
  * accessing it.
  *
- * This is a preferred way to to pin @mm for a longer/unbounded amount
+ * This is a preferred way to pin @mm for a longer/unbounded amount
  * of time.
  *
  * Use mmdrop() to release the reference acquired by mmgrab().
@@ -232,7 +232,7 @@ static inline unsigned int memalloc_noio_save(void)
  * @flags: Flags to restore.
  *
  * Ends the implicit GFP_NOIO scope started by memalloc_noio_save function.
- * Always make sure that that the given flags is the return value from the
+ * Always make sure that the given flags is the return value from the
  * pairing memalloc_noio_save call.
  */
 static inline void memalloc_noio_restore(unsigned int flags)
@@ -263,7 +263,7 @@ static inline unsigned int memalloc_nofs_save(void)
  * @flags: Flags to restore.
  *
  * Ends the implicit GFP_NOFS scope started by memalloc_nofs_save function.
- * Always make sure that that the given flags is the return value from the
+ * Always make sure that the given flags is the return value from the
  * pairing memalloc_nofs_save call.
  */
 static inline void memalloc_nofs_restore(unsigned int flags)