Kernel+Userland: Remove chroot functionality

We are not using this for anything and it's just been sitting there
gathering dust for well over a year, so let's stop carrying all this
complexity around for no good reason.

Kernel/init.cpp

@@ -325,8 +325,6 @@ void init_stage2(void*)
         PANIC("VirtualFileSystem::mount_root failed");
     }
 
-    Process::current()->set_root_directory(VirtualFileSystem::the().root_custody());
-
     // Switch out of early boot mode.
     g_in_early_boot = false;