test: run keventd from the configured libexec path

make distcheck fails in dbus-device:

    sh: /libexec/finit/keventd: not found

distcheck configures with --prefix=$(distdir)/_inst, so the bundled
helpers install below that prefix, not in /libexec/finit, which the test
had hard coded.

Export the configured pkglibexecdir as FINIT_EXECPATH in test.env and
run keventd from there, the same path finit itself is built with.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/dbus-device.sh

@@ -81,7 +81,7 @@ info=$(texec "$CLIENT" call-s "$DEVBUS" /org/finit/device \
 assert "Info answered for dummy0" 0 -eq 0
 
 say "keventd -S settles via the bus"
-run "/libexec/finit/keventd -S -t 15" || fail "keventd -S failed"
+run "$FINIT_EXECPATH/keventd -S -t 15" || fail "keventd -S failed"
 assert "bus-first settle ok" 0 -eq 0
 
 say "Trigger(add, net) re-emits events, DeviceProcessed observed"

test/test.env.in

@@ -4,3 +4,4 @@ exec_prefix=@exec_prefix@
 export TESTENV_PATH=/bin:/sbin:/usr/bin:/usr/sbin:"@bindir@":"@sbindir@"
 export FINIT_CONF="@FINIT_CONF@"
 export FINIT_RCSD="@FINIT_RCSD@"
+export FINIT_EXECPATH="@pkglibexecdir@"