Fixed backend function of objc_mutex_trylock which was broken

From-SVN: r44104

gcc/gthr-posix.h

@@ -331,9 +331,12 @@ __gthread_objc_mutex_deallocate(objc_mutex_t mutex)
 static inline int
 __gthread_objc_mutex_lock(objc_mutex_t mutex)
 {
-  if (__gthread_active_p ())
-    return pthread_mutex_lock((pthread_mutex_t *)mutex->backend);
-  else
+  if (__gthread_active_p () 
+      && pthread_mutex_lock((pthread_mutex_t *)mutex->backend) != 0)
+    {
+      return -1;
+    }
+
   return 0;
 }
 
@@ -341,9 +344,12 @@ __gthread_objc_mutex_lock(objc_mutex_t mutex)
 static inline int
 __gthread_objc_mutex_trylock(objc_mutex_t mutex)
 {
-  if (__gthread_active_p ())
-    return pthread_mutex_trylock((pthread_mutex_t *)mutex->backend);
-  else
+  if (__gthread_active_p () 
+      && pthread_mutex_trylock((pthread_mutex_t *)mutex->backend) != 0)
+    {
+      return -1;
+    }
+
   return 0;
 }
 
@@ -351,9 +357,12 @@ __gthread_objc_mutex_trylock(objc_mutex_t mutex)
 static inline int
 __gthread_objc_mutex_unlock(objc_mutex_t mutex)
 {
-  if (__gthread_active_p ())
-    return pthread_mutex_unlock((pthread_mutex_t *)mutex->backend);
-  else
+  if (__gthread_active_p () 
+      && pthread_mutex_unlock((pthread_mutex_t *)mutex->backend) != 0)
+    {
+      return -1;
+    }
+
   return 0;
 }