lint/kconfig: Fix check for IS_ENABLED(XXX) where someone forgot CONFIG_

This is a great check, but unfortunately it's currently not effective
because most uses of IS_ENABLED() do not have whitespace in front of
them (they're mostly used as part of an if (IS_ENABLED(...)) condition).
This patch makes the linter a little more generous in what it considers
in scope to avoid these false negatives in the future.

Change-Id: I2296410c73cd6e918465c90db33e782936bec0f9
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31746
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/util/lint/kconfig_lint b/util/lint/kconfig_lint
index eddd8de..dc01e71 100755
--- a/util/lint/kconfig_lint
+++ b/util/lint/kconfig_lint
@@ -236,11 +236,11 @@
     my @collected_is_enabled;
     if ($dont_use_git_grep) {
         @collected_is_enabled =
-            `grep -Irn -- "[[:space:]]IS_ENABLED[[:space:]]*(.*)" | grep -v '$exclude_dirs_and_files' | grep -v "kconfig.h"`;
+            `grep -Irn -- "\\<IS_ENABLED[[:space:]]*(.*)" | grep -v '$exclude_dirs_and_files' | grep -v "kconfig.h"`;
     }
     else {
         @collected_is_enabled =
-            `git grep -In -- "[[:space:]]IS_ENABLED[[:space:]]*(.*)" | grep -v '$exclude_dirs_and_files' | grep -v "kconfig.h"`;
+            `git grep -In -- "\\<IS_ENABLED[[:space:]]*(.*)" | grep -v '$exclude_dirs_and_files' | grep -v "kconfig.h"`;
     }
 
     while ( my $line = shift @collected_is_enabled ) {