util/lint/kconfig_lint: update help checking

- Turn the check for help text with no indentation from a warning to
an error.
- Show an error if the help text is at the same indentation level as
the 'help' keyword.

Change-Id: Ibf868c83e2a128ceb6c4d3da7f2cf7dc237054e6
Signed-off-by: Martin Roth <martinroth@google.com>
Reviewed-on: https://review.coreboot.org/19851
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

util/lint/kconfig_lint_README

@@ -45,7 +45,6 @@ Notes:
 Warnings in Kconfig files:
 - Any 'default' expressions that can never be reached.
 - Symbols that are defined but never used.
-- Help text starting with no whitespace.
 - Directories specified in a 'source' keyword do not exist.
 - A 'source' keyword loading a Kconfig file that has already been loaded.
 - A 'source' keyword loading a Kconfig file that doesn't exist. Note that
@@ -78,6 +77,8 @@ Errors in Kconfig files:
 - Lines not ending with a linefeed.  These can cause some keywords to not
   function properly ('source' keywords in particular).  It's also just
   generally good to end the file with a linefeed.
+- Help text starting with no whitespace.
+- Help text that starts at the same indentation level as the 'help' keyword.
 
 Errors in Kconfig that are also caught by Kconfig itself:
 - Invalid expressions.