mdadm: Fix building errors

In util.c, there is a building error:
'/md/metadata_version' directive writing 20 bytes into a
region of size between 0 and 255 [-Werror=format-overflow=]

In mapfile.c
It declares the fouth argument as 'int *' in map_update,
but in mdadm.h it's previously declared as an array 'int[4]'

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

mapfile.c

@@ -215,7 +215,7 @@ void map_free(struct map_ent *map)
 }
 
 int map_update(struct map_ent **mpp, char *devnm, char *metadata,
-	       int *uuid, char *path)
+	       int uuid[4], char *path)
 {
 	struct map_ent *map, *mp;
 	int rv;

util.c

@@ -1543,7 +1543,7 @@ int open_container(int fd)
 	/* 'fd' is a block device.  Find out if it is in use
 	 * by a container, and return an open fd on that container.
 	 */
-	char path[256];
+	char path[288];
 	char *e;
 	DIR *dir;
 	struct dirent *de;