some spinlocks were actually wait channels

kern/thread/synch.c

@@ -194,11 +194,11 @@ void lock_acquire(struct lock * lock)
     wchan_lock(lock->wc);
     spinlock_release(&(lock->spin));
     wchan_sleep(lock->wc);
-    spinlock_acquire(&(lock->wc));
+    spinlock_acquire(&(lock->spin));
   }
   
   lock->owner = curthread;
-  spinlock_release(&(lock->wc));
+  spinlock_release(&(lock->spin));
 }
 
 void lock_release(struct lock * lock)