shared: move assertion in _NM_UTILS_STRING_TABLE_LOOKUP_DEFINE()

Move the assertion for valid LIST first. It only checks static data,
and regardless of the entry_cmd, it should be done first.

Fixes: f4d12f7b59 ('shared: add NM_UTILS_STRING_TABLE_LOOKUP_STRUCT_DEFINE() macro for lookup of structs')

shared/nm-glib-aux/nm-shared-utils.h

@@ -1564,8 +1564,6 @@ fcn_name (const char *name) \
 		__VA_ARGS__ \
 	}; \
 	\
-	{ entry_cmd; } \
-	\
 	if (NM_MORE_ASSERT_ONCE (5)) { \
 		int i; \
 		\
@@ -1576,6 +1574,8 @@ fcn_name (const char *name) \
 		} \
 	} \
 	\
+	{ entry_cmd; } \
+	\
 	if (G_LIKELY (name)) { \
 		G_STATIC_ASSERT (G_N_ELEMENTS (LIST) > 1); \
 		G_STATIC_ASSERT (G_N_ELEMENTS (LIST) < G_MAXUINT / 2u - 10u); \