linux-user: fail and report on bad dfilter specs

Just passing NULL means we end up ignoring the bad dfilter spec
instead of reporting it and exiting as we should.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20190830143648.2967-1-alex.bennee@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
1 file changed