format-code: fail on markdownlint warnings

We've cleaned up the vast majority of markdownlint warnings and the
few remaining have pending commits.  Enable failures on markdownlint
warnings now so we do not regress.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I3e16bd65cf0b3aefc818b027c8b368dc56819332
diff --git a/scripts/format-code.sh b/scripts/format-code.sh
index 5598f13..f49a027 100755
--- a/scripts/format-code.sh
+++ b/scripts/format-code.sh
@@ -255,9 +255,7 @@
 LINTER_IGNORE+=([markdownlint]=".markdownlint-ignore")
 LINTER_TYPES+=([markdownlint]="markdown")
 function do_markdownlint() {
-    markdownlint --config "${LINTER_CONFIG[markdownlint]}" -- "$@" || \
-        echo -e "    ${YELLOW}Failed markdownlint; temporarily ignoring."
-    # We disable line-length because prettier should handle prose wrap for us.
+    markdownlint --config "${LINTER_CONFIG[markdownlint]}" -- "$@"
 }
 
 LINTER_REQUIRE+=([meson]="meson;meson.build")