increase chroot tmpfs size

cp: error copying '/var/tmp/dracut.dgkRVtH/initramfs.img' to
'/tmp/kernel-install.staging.pz8r83/initrd': No space left on device

Author: anokfireball

features/_pxe/image.pxe.tar.gz

@@ -11,7 +11,7 @@ pushd "$dir" > /dev/null
 export PATH="/builder/image.d:$PATH"
 
 chroot_dir="$(mktemp -d)"
-mount -t tmpfs tmpfs "$chroot_dir"
+mount -t tmpfs -o size=4G tmpfs "$chroot_dir"
 tar --extract --xattrs --xattrs-include '*' --directory "$chroot_dir" < "$input"
 
 cp "$chroot_dir/boot/"vmlinuz* vmlinuz