fmf: Strengthen integration test

Enable `pipefail` shell option.

Reduce timeout, this should take not even a second.

Author: martinpitt

tests/main.fmf

@@ -1,14 +1,14 @@
 summary: smoke test
-duration: 10m
+duration: 1m
 require:
   - python3-dbusmock
 test: |
-  set -eux
+  set -eux -o pipefail
   python3 -m dbusmock com.example.Foo / com.example.Foo.Manager &
   MOCK=$!
   trap "kill $MOCK; wait $MOCK || true" EXIT INT QUIT PIPE
 
-  until busctl list --user | grep -q com.example.Foo; do sleep 0.1; done
+  until busctl list --user | grep -q com.example.Foo; do sleep 0.5; done
 
   busctl call --user com.example.Foo / org.freedesktop.DBus.Mock AddMethod sssss '' 'Ping' '' '' ''
   busctl introspect --user com.example.Foo / com.example.Foo.Manager | grep Ping