fs: run filesystem hooks under fakeroot

Currently, the pre-gen hooks of the various filesystems are run before
we enter the fakeroot.

However, this precludes those hooks from doing actions that require
root, like creating a pseudo-device or the likes.

So, move those pre-gen hooks under fakeroot.

This has currently no side-effect, as they are still called before
everything else in the fakeroot script, even the system-wide chown call.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

fs/common.mk

@@ -76,9 +76,10 @@ $$(BINARIES_DIR)/rootfs.$(1): target-finalize $$(ROOTFS_$(2)_DEPENDENCIES)
 	@$$(call MESSAGE,"Generating root filesystem image rootfs.$(1)")
 	rm -rf $(FS_DIR)
 	mkdir -p $(FS_DIR)
-	$$(foreach hook,$$(ROOTFS_$(2)_PRE_GEN_HOOKS),$$(call $$(hook))$$(sep))
 	echo '#!/bin/sh' > $$(FAKEROOT_SCRIPT)
 	echo "set -e" >> $$(FAKEROOT_SCRIPT)
+	$$(foreach hook,$$(ROOTFS_$(2)_PRE_GEN_HOOKS),\
+		$$(call PRINTF,$$($$(hook))) >> $$(FAKEROOT_SCRIPT)$$(sep))
 	echo "chown -h -R 0:0 $$(TARGET_DIR)" >> $$(FAKEROOT_SCRIPT)
 ifneq ($$(ROOTFS_USERS_TABLES),)
 	cat $$(ROOTFS_USERS_TABLES) >> $$(USERS_TABLE)