criu: pagemap: close pagemap image before returning from init_pagemaps

Fix CID 163578 (#1 of 1): Structurally dead code (UNREACHABLE).
The pagemap image would never be closed because of stupid code order in
the original patch (674583f2: criu: page-read: read pagemaps at open time
and keep them in memory).
Fix that.
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/pagemap.c

@@ -396,11 +396,11 @@ static int init_pagemaps(struct page_read *pr)
 		}
 	}
 
-	return 0;
-
 	close_image(pr->pmi);
 	pr->pmi = NULL;
 
+	return 0;
+
 free_pagemaps:
 	free_pagemaps(pr);
 	return -1;