media-plugins/vdr-vdrmanager: Replace unnecessary path_exists call

Replace the unnecessary path_exists calls with plain bash -f test.
The path_exists function was only intended to be used when necessary
to deal with wildcards.

Closes: https://bugs.gentoo.org/662178

media-plugins/vdr-vdrmanager/vdr-vdrmanager-0.14.ebuild

@@ -63,7 +63,7 @@ pkg_postinst() {
 	einfo "Add a password to /etc/conf.d/vdr.vdrmanager"
 
 	if use ssl ; then
-		if path_exists -a "${ROOT}${VDRMANAGER_SSL_KEY_FILE}.pem"; then
+		if [[ -f ${ROOT}${VDRMANAGER_SSL_KEY_FILE}.pem ]]; then
 			einfo "found an existing SSL cert, to create a new SSL cert, run:\n"
 			einfo "emerge --config ${PN}"
 		else