Add in a few missing -2023 dates in copyright notice

Change-Id: Iba9367ba8e4cd395789d58b7ded52e74459af6c8
diff --git a/makefiles/lint/shell.mk b/makefiles/lint/shell.mk
index a02da31..704038c 100644
--- a/makefiles/lint/shell.mk
+++ b/makefiles/lint/shell.mk
@@ -34,7 +34,7 @@
 shell-check      := shellcheck
 
 shell-check-args += --check-sourced
-shell-check-args += --extenal-sources
+shell-check-args += --external-sources
 
 ##-------------------##
 ##---]  TARGETS  [---##