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

The error variable in snapshot_write_next() gets a value before it is
used, so don't initialize it to 0 upfront.
Signed-off-by: Li zeming <zeming@nfschina.com>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/snapshot.c

@@ -2778,7 +2778,7 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
 int snapshot_write_next(struct snapshot_handle *handle)
 {
 	static struct chain_allocator ca;
-	int error = 0;
+	int error;
 
 next:
 	/* Check if we have already loaded the entire image */