PM: hibernate: Correct spelling mistake in a comment

Fix a typo in a comment in kernel/power/snapshot.c
Signed-off-by: Wang Honghui <honghui.wang@ucas.com.cn>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/snapshot.c

@@ -398,7 +398,7 @@ struct mem_zone_bm_rtree {
 	unsigned int blocks;		/* Number of Bitmap Blocks     */
 };
 
-/* strcut bm_position is used for browsing memory bitmaps */
+/* struct bm_position is used for browsing memory bitmaps */
 
 struct bm_position {
 	struct mem_zone_bm_rtree *zone;