'make all' failure requires PATH be set.

Created by: ianmiell

FWIW, my install failed with this:

imiell@welles:~/redox/redox  ⑂ master  $  make all
mkdir -p build
nasm -f bin -o build/bootloader -D ARCH_x86_64 -ibootloader/x86_64/ bootloader/x86_64/disk.asm
cd kernel && xargo clean
/bin/sh: 1: xargo: not found
mk/initfs.mk:2: recipe for target 'build/initfs.tag' failed
make: *** [build/initfs.tag] Error 127

so I set:

PATH=${PATH}:/home/imiell/.cargo/bin

and make all worked.