Switch getline_nohang from XFAIL to UNSUPPORTED for NetBSD
This test sometimes works, usually breaks.
// RUN: %clangxx_tsan -O1 %s -o %t && %run %t
-// Data race triggered.
-// XFAIL: netbsd
+// Data race randomly triggered.
+// UNSUPPORTED: netbsd
// Make sure TSan doesn't deadlock on a file stream lock at program shutdown.
// See https://github.com/google/sanitizers/issues/454
