PM / hibernate: Drop redundant parameter of swsusp_alloc()

The first parameter of swsusp_alloc is not used, so drop it.

Signed-off-by: BaoJun Luo <baojun.luo@samsung.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>