tests: drop "-z" from fusermount to catch forgotten fds

macos does not have lazy unmount, so let's not use it
on linux either.
If the unmount fails, run "lsof" to find the open file.

Also fix the first bug we found this way.

1 files changed, 1 insertions, 0 deletions

diff --git a/tests/matrix/matrix_test.go b/tests/matrix/matrix_test.go
index f492001..574f11f 100644
--- a/tests/matrix/matrix_test.go
+++ b/tests/matrix/matrix_test.go
@@ -796,6 +796,7 @@ func TestUtimesNanoFd(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer f.Close()
 	procPath := fmt.Sprintf("/proc/self/fd/%d", f.Fd())
 	doTestUtimesNano(t, procPath)
 }