When linux-specific commands (including guest-fsfreeze-*) were consolidated
under defined(__linux__), we forgot to account for the case where
defined(__linux__) && !defined(FIFREEZE). As a result stubs are no longer
being generated on linux hosts that don't have FIFREEZE support. Fix
this.
Tested-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>