main/udev: make sure /dev/fd is a symlink to /proc/self/fd

ref #1465

main/udev/APKBUILD

 # Maintainer: Natanael Copa <ncopa@alpinelinux.org>
 pkgname=udev
 pkgver=175
-pkgrel=4
+pkgrel=5
 pkgdesc="The userspace dev tools (udev)"
 url="http://www.kernel.org/pub/linux/utils/kernel/hotplug/"
 arch="all"
@@ -74,6 +74,6 @@ libgudev() {
 
 md5sums="2fc9c1efcbde98e3d73ffee7a77aea47  udev-175.tar.bz2
 c9de7581099cdfdcd105666cd98a0f0a  write_root_link_rule
-884d7faaaa149a323b14e907ea1934f4  udev-mount.initd
+bfc97ba47f6db2b6ae458a65c0b396d5  udev-mount.initd
 e99c87e62e7cb5acc4c55bf065944a11  udev-postmount.initd
 c11fb3517a567db9994d5f9dbc88ecae  udev.initd"

main/udev/udev-mount.initd

@@ -44,6 +44,8 @@ seed_dev()
 
 	# Create problematic directories
 	mkdir -p /dev/pts /dev/shm
+	rm -rf /dev/fd
+	ln -snf /proc/self/fd /dev/fd
 	return 0
 }