PM: hibernate: fix the kerneldoc comment for swsusp_check() and swsusp_close()

The comments for both swsusp_check() and swsusp_close() don't actually
describe what they are doing.

Just removing the comments would probably better, but as the file is
full of useless kerneldoc comments for non-exported symbols this fits
in better with the style.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>