mstflint: fix signature issue (#5427)

SPECS-SIGNED/kernel-mstflint-signed/kernel-mstflint-signed.spec

@@ -1,4 +1,6 @@
 %global debug_package %{nil}
+# The default %%__os_install_post macro ends up stripping the signatures off of the kernel module.
+%define __os_install_post %{__os_install_post_leave_signatures} %{nil}
 %define mstflint_unsigned_name kernel-mstflint
 %define mstflint_module_name mstflint_access.ko
 %define ub_kver 5.16.0
@@ -47,7 +49,7 @@ depmod %{kver}
 
 %files -n %{mstflint_unsigned_name}
 %defattr(-,root,root,-)
-/%{install_mod_dir}/
+%{install_mod_dir}
 
 %changelog
 * Thu Mar 23 2023 Elaheh Dehghani <edehghani@microsoft.com> - 4.21.0-4