hello-mt: fix pthread porting issue

Properly use pthread_mutex_destroy as equivalent for cthreads' mutex_clear, instead of pthread_mutex_init.
Issue kindly reported by Nick Lloyd, thanks!

* trans/hello-mt.c (close_hook): Call pthread_mutex_destroy instead of
pthread_mutex_init.

1 files changed, 1 insertions, 1 deletions

diff --git a/trans/hello-mt.c b/trans/hello-mt.c
index 632d3730..c2d4cc99 100644
--- a/trans/hello-mt.c
+++ b/trans/hello-mt.c
@@ -111,7 +111,7 @@ close_hook (struct trivfs_peropen *peropen)
 {
   struct open *op = peropen->hook;
 
-  pthread_mutex_init (&op->lock, NULL);
+  pthread_mutex_destroy (&op->lock);
   free (op);
 }