test/ftl: Prevent from trying to kill same process twice

ftl fio tests should not kill spdk_tgt process on exit.

Change-Id: I541e84002202a5f01bd5a2dffe31a60e02da30e9
Signed-off-by: Wojciech Malikowski <wojciech.malikowski@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/1179
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

test/ftl/fio.sh

@@ -59,6 +59,7 @@ waitforbdev ftl0
 ) > $FTL_JSON_CONF
 
 killprocess $svcpid
+trap - SIGINT SIGTERM EXIT
 
 for test in ${tests}; do
 	timing_enter $test
@@ -66,5 +67,5 @@ for test in ${tests}; do
 	timing_exit $test
 done
 
-trap - SIGINT SIGTERM EXIT
-fio_kill
+rm -f $ftl_bdev_conf
+rm -f $FTL_JSON_CONF