fileutils: Add LIBGSYSTEM_ENABLE_GUESTFS_FUSE_WORKAROUND environment variable
fileutils: Add LIBGSYSTEM_ENABLE_GUESTFS_FUSE_WORKAROUND environment variable

This ugly hack is necessary because for some reason guestmount/fuse gives
me ENOENT, when it should be returning EXDEV.

GNOME/libgsystem,Distrotech/libgsystem,GNOME/libgsystem,Distrotech/libgsystem