vty: Remove two unimplemented OML functions

attribute get|set <0-255> (.HEX) was never implemented and the
output about the unused attributes clutter the build output, remove
them.

GCC warning:
abis_nm_vty.c: In function ‘oml_attrib_get’:
abis_nm_vty.c:141:25: warning: unused variable ‘oms’ [-Wunused-variable]
abis_nm_vty.c: In function ‘oml_attrib_set’:
abis_nm_vty.c:152:25: warning: unused variable ‘oms’ [-Wunused-variable]
diff --git a/openbsc/src/libbsc/abis_nm_vty.c b/openbsc/src/libbsc/abis_nm_vty.c
index bcbc92d..6ac4a9e 100644
--- a/openbsc/src/libbsc/abis_nm_vty.c
+++ b/openbsc/src/libbsc/abis_nm_vty.c
@@ -133,28 +133,6 @@
 	return CMD_SUCCESS;
 }
 
-DEFUN(oml_attrib_get, oml_attrib_get_cmd,
-	"attribute get <0-255>",
-	"OML Attribute Actions\n" "Get a single OML Attribute\n"
-	"OML Attribute Number\n")
-{
-	struct oml_node_state *oms = vty->index;
-
-	/* FIXME */
-	return CMD_SUCCESS;
-}
-
-DEFUN(oml_attrib_set, oml_attrib_set_cmd,
-	"attribute set <0-255> .HEX",
-	"OML Attribute Actions\n" "Set a single OML Attribute\n"
-	"OML Attribute Number\n")
-{
-	struct oml_node_state *oms = vty->index;
-
-	/* FIXME */
-	return CMD_SUCCESS;
-}
-
 DEFUN(oml_chg_adm_state, oml_chg_adm_state_cmd,
 	"change-adm-state (locked|unlocked|shutdown|null)",
 	"Change the Administrative State\n"
@@ -190,8 +168,6 @@
 
 	install_default(OML_NODE);
 	install_element(OML_NODE, &ournode_exit_cmd);
-	install_element(OML_NODE, &oml_attrib_get_cmd);
-	install_element(OML_NODE, &oml_attrib_set_cmd);
 	install_element(OML_NODE, &oml_chg_adm_state_cmd);
 	install_element(OML_NODE, &oml_opstart_cmd);