Switch getline_nohang from XFAIL to UNSUPPORTED for NetBSD

This test sometimes works, usually breaks.

llvm-svn: 345655

compiler-rt/test/tsan/getline_nohang.cc

@@ -1,7 +1,7 @@
 // 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