Revert "Add exemption for make.bat in checks for tabs"

This is no longer needed as make.bat has been removed. We do not support
building the documentation on Windows.

This reverts commit d50daedccace24bf69903ff7879bc0543757f5ef.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/tests/scripts/check_files.py b/tests/scripts/check_files.py
index 7cb3e0b..352b55e 100755
--- a/tests/scripts/check_files.py
+++ b/tests/scripts/check_files.py
@@ -350,7 +350,6 @@
         ".sln",
         "/Makefile",
         "/Makefile.inc",
-        "/make.bat",
         "/generate_visualc_files.pl",
     ])