ethtool: use NM_MORE_ASSERT_ONCE() in _ASSERT_data() to assert immutable data only once

_ASSERT_data() checks static, immutable data. Even with more asserts enabled,
there is no need to do that every time. Use NM_MORE_ASSERT_ONCE().

Note that NM_MORE_ASSERT_ONCE() will return constant FALSE, when build
without a sufficiently high assertion level. That means, the compiler
will just optimize the rest away.

shared/nm-libnm-core-intern/nm-ethtool-utils.c

@@ -135,9 +135,11 @@ static const guint8 _by_name[_NM_ETHTOOL_ID_NUM] = {
 static void
 _ASSERT_data (void)
 {
-#if NM_MORE_ASSERTS > 10
 	int i;
 
+	if (!NM_MORE_ASSERT_ONCE (10))
+		return;
+
 	G_STATIC_ASSERT_EXPR (_NM_ETHTOOL_ID_FIRST == 0);
 	G_STATIC_ASSERT_EXPR (_NM_ETHTOOL_ID_LAST == _NM_ETHTOOL_ID_NUM - 1);
 	G_STATIC_ASSERT_EXPR (_NM_ETHTOOL_ID_NUM > 0);
@@ -173,7 +175,6 @@ _ASSERT_data (void)
 			}
 		}
 	}
-#endif
 }
 
 static int