fsmonitor: mark unused parameters in stub functions
The fsmonitor code has some platform-specific functions for which one or
more platforms implement noop or stub functions. We can't get rid of
these functions nor change their interface, since the point is to match
their equivalents in other platforms. But let's annotate their
parameters to quiet the compiler's -Wunused-parameter warning.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>