build: Minor - fix comments referring to old tools/ directory.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/scripts/checkstack.py b/scripts/checkstack.py
index 62fef36..e86a649 100755
--- a/scripts/checkstack.py
+++ b/scripts/checkstack.py
@@ -7,7 +7,7 @@
 # This file may be distributed under the terms of the GNU GPLv3 license.
 
 # Usage:
-#   objdump -m i386 -M i8086 -M suffix -d out/rom16.o | tools/checkstack.py
+#   objdump -m i386 -M i8086 -M suffix -d out/rom16.o | scripts/checkstack.py
 
 import sys
 import re