mm/memcontrol.c: move comments for get_mctgt_type() to proper position

Move the comments for get_mctgt_type() to be before get_mctgt_type()
implementation.

Link: http://lkml.kernel.org/r/1463644638-7446-1-git-send-email-roy.qing.li@gmail.comSigned-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -4309,24 +4309,6 @@ static int mem_cgroup_do_precharge(unsigned long count)
 	return 0;
 }
 
-/**
- * get_mctgt_type - get target type of moving charge
- * @vma: the vma the pte to be checked belongs
- * @addr: the address corresponding to the pte to be checked
- * @ptent: the pte to be checked
- * @target: the pointer the target page or swap ent will be stored(can be NULL)
- *
- * Returns
- *   0(MC_TARGET_NONE): if the pte is not a target for move charge.
- *   1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
- *     move charge. if @target is not NULL, the page is stored in target->page
- *     with extra refcnt got(Callers should handle it).
- *   2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
- *     target for charge migration. if @target is not NULL, the entry is stored
- *     in target->ent.
- *
- * Called with pte lock held.
- */
 union mc_target {
 	struct page	*page;
 	swp_entry_t	ent;
@@ -4515,6 +4497,25 @@ static int mem_cgroup_move_account(struct page *page,
 	return ret;
 }
 
+/**
+ * get_mctgt_type - get target type of moving charge
+ * @vma: the vma the pte to be checked belongs
+ * @addr: the address corresponding to the pte to be checked
+ * @ptent: the pte to be checked
+ * @target: the pointer the target page or swap ent will be stored(can be NULL)
+ *
+ * Returns
+ *   0(MC_TARGET_NONE): if the pte is not a target for move charge.
+ *   1(MC_TARGET_PAGE): if the page corresponding to this pte is a target for
+ *     move charge. if @target is not NULL, the page is stored in target->page
+ *     with extra refcnt got(Callers should handle it).
+ *   2(MC_TARGET_SWAP): if the swap entry corresponding to this pte is a
+ *     target for charge migration. if @target is not NULL, the entry is stored
+ *     in target->ent.
+ *
+ * Called with pte lock held.
+ */
+
 static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
 		unsigned long addr, pte_t ptent, union mc_target *target)
 {