PM: hibernate: Do not initialize error in swap_write_page()

'error' first receives the function result before it is used, and it
does not need to be assigned a value during definition.
Signed-off-by: Li zeming <zeming@nfschina.com>
[ rjw: Subject rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/swap.c

@@ -451,7 +451,7 @@ static int get_swap_writer(struct swap_map_handle *handle)
 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 		struct hib_bio_batch *hb)
 {
-	int error = 0;
+	int error;
 	sector_t offset;
 
 	if (!handle->cur)