test: do not ignore 'tools/benchmark/cmd'

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

test

@@ -27,7 +27,7 @@ fi
 COVER=${COVER:-"-cover"}
 
 # Hack: gofmt ./ will recursively check the .git directory. So use *.go for gofmt.
-IGNORE_PKGS="(cmd|vendor|etcdserverpb|rafttest|gopath.proto|v3lockpb|v3electionpb)"
+IGNORE_PKGS="(cmd/|etcdserverpb|rafttest|gopath.proto|v3lockpb|v3electionpb)"
 INTEGRATION_PKGS="(integration|e2e|contrib|functional-tester)"
 
 # all github.com/coreos/etcd/whatever pkgs that are not auto-generated / tools