mm/mempolicy: fix mpol_misplaced kernel-doc

mainline inclusion
from mainline-5.13-rc1
commit 5f076944
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I3ZVL2
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f076944f06988391a6dbd458fc6485a71088e57

-------------------------------------------------

Sphinx interprets the Return section as a list and complains about it.
Turn it into a sentence and move it to the end of the kernel-doc to fit
the kernel-doc style.

Link: https://lkml.kernel.org/r/20210225150642.2582252-8-willy@infradead.orgSigned-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 5f076944)
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>
(fix conflicts: add "kernel-doc:: mm/mempolicy.c" at the end of mm-api.rst)
Reviewed-by: NTong Tiangen <tongtiangen@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

Documentation/core-api/mm-api.rst

@@ -95,3 +95,4 @@ More Memory Management Functions
    :export:
 
 .. kernel-doc:: mm/page_alloc.c
+.. kernel-doc:: mm/mempolicy.c

mm/mempolicy.c

@@ -2442,14 +2442,11 @@ static void sp_free(struct sp_node *n)
  * @addr: virtual address where page mapped
  *
  * Lookup current policy node id for vma,addr and "compare to" page's
- * node id.
- *
- * Returns:
- *	-1	- not misplaced, page is in the right node
- *	node	- node id where the page should be
- *
- * Policy determination "mimics" alloc_page_vma().
+ * node id.  Policy determination "mimics" alloc_page_vma().
  * Called from fault path where we know the vma and faulting address.
+ *
+ * Return: -1 if the page is in a node that is valid for this policy, or a
+ * suitable node ID to allocate a replacement page from.
  */
 int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
 {