[init] Show initialisation function names in debug messages

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/init.h

@@ -12,6 +12,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  * call to initialise().
  */
 struct init_fn {
+	const char *name;
 	void ( * initialise ) ( void );
 };