payloads/GRUB: Use correct script name in Makefile

Fixes: 3555389a8c (payloads: Update GRUB stable from 2.02 to 2.04)
Change-Id: I2f95059453ca5565a38550b147590ece4d8bf5ad
Signed-off-by: Gompa <gompa@h-bomb.nl>
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34366
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/payloads/external/GRUB2/Makefile b/payloads/external/GRUB2/Makefile
index 43da597..b433bc0 100644
--- a/payloads/external/GRUB2/Makefile
+++ b/payloads/external/GRUB2/Makefile
@@ -28,7 +28,7 @@
 	echo "    CONFIG     GRUB2 $(NAME-y)"
 	rm -rf grub2/build
 	mkdir grub2/build
-	cd grub2 && ./bootstrap.sh ; ./autogen.sh
+	cd grub2 && ./bootstrap ; ./autogen.sh
 	cd grub2/build && ../configure CC="$(HOSTCC)" LD="$(LD)" \
 	FREETYPE="pkg-config freetype2" BUILD_FREETYPE="pkg-config freetype2" \
 	TARGET_CC="$(CC)" TARGET_OBJCOPY="$(OBJCOPY)" TARGET_STRIP="$(STRIP)" \