dtoc: Correct remaining pylint problems in test_fdt

Fix various camel-case and other naming problems. Update the pylint base
file to avoid regressions.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/scripts/pylint.base b/scripts/pylint.base
index dd6360e..c7d141e 100644
--- a/scripts/pylint.base
+++ b/scripts/pylint.base
@@ -167,7 +167,7 @@
 tools_binman_etype_x86_start16 -15.71
 tools_binman_etype_x86_start16_spl -15.71
 tools_binman_etype_x86_start16_tpl -15.71
-tools_binman_fdt_test 3.23
+tools_binman_fdt_test 10.00
 tools_binman_fip_util 9.85
 tools_binman_fip_util_test 10.00
 tools_binman_fmap_util 6.88