mm: fix page_alloc.c kernel-doc warnings

Fix kernel-doc warnings and function name in mm/page_alloc.c:

  Warning(..//mm/page_alloc.c:6074): No description found for parameter 'pfn'
  Warning(..//mm/page_alloc.c:6074): No description found for parameter 'mask'
  Warning(..//mm/page_alloc.c:6074): Excess function parameter 'start_bitidx' description in 'get_pfnblock_flags_mask'
  Warning(..//mm/page_alloc.c:6102): No description found for parameter 'pfn'
  Warning(..//mm/page_alloc.c:6102): No description found for parameter 'mask'
  Warning(..//mm/page_alloc.c:6102): Excess function parameter 'start_bitidx' description in 'set_pfnblock_flags_mask'
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Acked-by: NMel Gorman <mgorman@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/page_alloc.c

@@ -6062,11 +6062,13 @@ static inline int pfn_to_bitidx(struct zone *zone, unsigned long pfn)
 }
 
 /**
- * get_pageblock_flags_group - Return the requested group of flags for the pageblock_nr_pages block of pages
+ * get_pfnblock_flags_mask - Return the requested group of flags for the pageblock_nr_pages block of pages
  * @page: The page within the block of interest
- * @start_bitidx: The first bit of interest to retrieve
- * @end_bitidx: The last bit of interest
- * returns pageblock_bits flags
+ * @pfn: The target page frame number
+ * @end_bitidx: The last bit of interest to retrieve
+ * @mask: mask of bits that the caller is interested in
+ *
+ * Return: pageblock_bits flags
  */
 unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
 					unsigned long end_bitidx,
@@ -6091,9 +6093,10 @@ unsigned long get_pfnblock_flags_mask(struct page *page, unsigned long pfn,
 /**
  * set_pfnblock_flags_mask - Set the requested group of flags for a pageblock_nr_pages block of pages
  * @page: The page within the block of interest
- * @start_bitidx: The first bit of interest
- * @end_bitidx: The last bit of interest
  * @flags: The flags to set
+ * @pfn: The target page frame number
+ * @end_bitidx: The last bit of interest
+ * @mask: mask of bits that the caller is interested in
  */
 void set_pfnblock_flags_mask(struct page *page, unsigned long flags,
 					unsigned long pfn,