util-lib: move fstab_node_to_udev_node() to fstab-util.[ch]

src/basic/device-nodes.h

@@ -21,5 +21,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
+#include <sys/types.h>
+
 int encode_devnode_name(const char *str, char *str_enc, size_t len);
 int whitelisted_char_for_devnode(char c, const char *additional);