grub.cfg: remove unnecessary path for isolinux

the path "/boot/EFI" is unnecessary because the ESP
is always a FAT32 partition, so we don't need to
scan it as a subdirectory within a subdirectory.

the ESP is always mounted as its own partition,
FAT32, and EFI/ is always at the root of it

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

config/grub/config/grub.cfg

@@ -98,7 +98,7 @@ function search_grub {
 
 function try_isolinux_config {
 	set root="${1}"
-	for dir in '' /boot /EFI /boot/EFI /@ /@/boot; do
+	for dir in '' /boot /EFI /@ /@/boot; do
 		if [ -f "${dir}"/isolinux/isolinux.cfg ]; then
 			syslinux_configfile -i "${dir}"/isolinux/isolinux.cfg
 		elif [ -f "${dir}"/syslinux/syslinux.cfg ]; then