Change to proper directory for the mod-sign.sh to work.

SPECS/kernel-lt-6.1.spec

@@ -698,7 +698,9 @@ popd > /dev/null
 %define __modsign_install_post \
 if [ "%{signmodules}" -eq "1" ]; then \
 	if [ "%{with_std}" -ne "0" ]; then \
+		cd linux-%{KVERREL} \
 		%{SOURCE21} certs/signing_key.pem.sign certs/signing_key.x509.sign $RPM_BUILD_ROOT/lib/modules/%{KVERREL}/ \
+		cd - \
 	fi \
 fi \
 if [ "%{zipmodules}" -eq "1" ]; then \