Quote 'threads' in test.pl

If unquoted, it may throw a warning when threads.pm can't be loaded.

1 files changed, 1 insertions, 1 deletions

diff --git a/t/test.pl b/t/test.pl
index b58013df77..088c7e3a76 100644
--- a/t/test.pl
+++ b/t/test.pl
@@ -981,7 +981,7 @@ sub watchdog ($;$)
     # Use a watchdog thread because either 'threads' is loaded,
     #   or fork() failed
     if (eval 'require threads; 1') {
-        threads->create(sub {
+        'threads'->create(sub {
                 # Load POSIX if available
                 eval { require POSIX; };