tools: hv: report ENOSPC errors in hv_fcopy_daemon

Currently some "Unspecified error 0x80004005" is reported on the Windows
side if something fails. Handle the ENOSPC case and return
ERROR_DISK_FULL, which allows at least Copy-VMFile to report a meaning
full error.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>