package/btrfs-progs: don't install host udev files

Pass an empty value for udevdir to avoid the following host build
failure on one of the autobuilders:

/usr/bin/install -c -m755 -d /usr/lib/udev/rules.d
/usr/bin/install -c -m644 64-btrfs-dm.rules 64-btrfs-zoned.rules /usr/lib/udev/rules.d
/usr/bin/install: cannot create regular file '/usr/lib/udev/rules.d/64-btrfs-dm.rules': Permission denied
/usr/bin/install: cannot create regular file '/usr/lib/udev/rules.d/64-btrfs-zoned.rules': Permission denied

This build failure can be raised since the addition of the host variant
in commit ed69859a7261ee86e71aa666d30a28e374769e15. udev rules were
added by upstream in 2016 by
https://github.com/kdave/btrfs-progs/commit/62c0666378eb70285b6a3052bf4144d2132a5891

Fixes: ed69859a7261ee86e71aa666d30a28e374769e15
 - http://autobuild.buildroot.org/results/c46238afe8d23cf4bff4e7290a5eaebd0640eb6e

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 8ce17e304b02c6969e4fd51f0bde97798d49eb3b)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/btrfs-progs/btrfs-progs.mk

@@ -59,5 +59,7 @@ HOST_BTRFS_PROGS_CONF_OPTS = \
 	--disable-python \
 	--disable-convert
 
+HOST_BTRFS_PROGS_INSTALL_OPTS = udevdir= install
+
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))