PM / hibernate: fix typo "reserverd_size" -> "reserved_size"

Fix a mistake in a variable name in a comment.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/snapshot.c

@@ -1681,7 +1681,7 @@ static unsigned long minimum_image_size(unsigned long saveable)
  * hibernation for allocations made while saving the image and for device
  * drivers, in case they need to allocate memory from their hibernation
  * callbacks (these two numbers are given by PAGES_FOR_IO (which is a rough
- * estimate) and reserverd_size divided by PAGE_SIZE (which is tunable through
+ * estimate) and reserved_size divided by PAGE_SIZE (which is tunable through
  * /sys/power/reserved_size, respectively).  To make this happen, we compute the
  * total number of available page frames and allocate at least
  *