grub.cfg: don't search for *_grub.cfg

this is a relic from the old days when we didn't
automated the grub.cfg logic as much. these days,
the grub.cfg logic is able to boot almost all distros
without any manual intervention or override.

removing these entries will speed up the boot in general

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/grub/config/grub.cfg

@@ -66,12 +66,10 @@ function try_user_config {
 
 	# The @/... entries are for cases where the BTRFS filesystem is being used
 	for dir in boot grub grub2 boot/grub boot/grub2 @/boot @/grub @/grub2 @/boot/grub @/boot/grub2; do
-		for name in '' osboot_ autoboot_ libreboot_ coreboot_; do
-			if [ -f /"${dir}"/"${name}"grub.cfg ]; then
-				unset superusers
-				configfile /"${dir}"/"${name}"grub.cfg
-			fi
-		done
+		if [ -f /"${dir}"/grub.cfg ]; then
+			unset superusers
+			configfile /"${dir}"/grub.cfg
+		fi
 	done
 }
 function search_grub {