libcomposefs: drop using "ro" option

MS_RDONLY is enough to mount the image as read-only.

Signed-off-by: Giuseppe Scrivano <[email protected]>

libcomposefs/lcfs-mount.c

@@ -580,7 +580,7 @@ static errint_t lcfs_mount_erofs(const char *source, const char *target,
 		return -ENOTSUP;
 
 	res = mount(source, target, "erofs", MS_RDONLY,
-		    image_has_acls ? "ro" : "ro,noacl");
+		    image_has_acls ? NULL : "noacl");
 	if (res < 0)
 		return -errno;