lint/lint-stable-003-whitespace: Fix excludelist

Remove the last slash '/' from directories in excludelist, so that they
will be correctly filtered by grep.

Fixes:
grep: util/goswid: Is a directory
grep: util/nvidia/cbootimage: Is a directory

Signed-off-by: Maximilian Brune <maximilian.brune@9elements.com>
Change-Id: I90cc2cff9a98bbd0af344156332b970bfd6430b9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73396
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
diff --git a/util/lint/lint-stable-003-whitespace b/util/lint/lint-stable-003-whitespace
index 838ea93..82b46b0 100755
--- a/util/lint/lint-stable-003-whitespace
+++ b/util/lint/lint-stable-003-whitespace
@@ -11,7 +11,7 @@
 # shellcheck source=helper_functions.sh
 . "${LINTDIR}/helper_functions.sh"
 
-EXCLUDELIST='^src/vendorcode/|^util/kconfig/|^util/nvidia/cbootimage/|^util/goswid/|__pycache__|COPYING|LICENSE|README|_shipped$|\.patch$|\.bin$|\.hex$|\.jpg$|\.gif$|\.ttf$|\.woff$|\.png$|\.eot$|\.vbt$|\.ico$|\.md$'
+EXCLUDELIST='^src/vendorcode/|^util/kconfig/|^util/nvidia/cbootimage|^util/goswid|__pycache__|COPYING|LICENSE|README|_shipped$|\.patch$|\.bin$|\.hex$|\.jpg$|\.gif$|\.ttf$|\.woff$|\.png$|\.eot$|\.vbt$|\.ico$|\.md$'
 INCLUDELIST="src util payloads Makefile* toolchain.inc tests"
 
 # shellcheck disable=SC2086,SC2046