PM / hibernate: fix a comment typo

Just fix a typo in a function name in kerneldoc comments.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/hibernate.c

@@ -733,7 +733,7 @@ int hibernate(void)
  * contents of memory is restored from the saved image.
  *
  * If this is successful, control reappears in the restored target kernel in
- * hibernation_snaphot() which returns to hibernate().  Otherwise, the routine
+ * hibernation_snapshot() which returns to hibernate().  Otherwise, the routine
  * attempts to recover gracefully and make the kernel return to the normal mode
  * of operation.
  */