Fix allocator calls

Destructors.rest

@@ -210,15 +210,15 @@ The current design for an allocator looks like this:
 
   proc alloc*(size: int): pointer =
     let a = getCurrentAllocator()
-    result = a.alloc(a, size)
+    result = a.alloc(p, size)
 
   proc dealloc*(p: pointer; size: int) =
     let a = getCurrentAllocator()
-    a.dealloc(a, size)
+    a.dealloc(p, size)
 
   proc realloc*(p: pointer; oldSize, newSize: int): pointer =
     let a = getCurrentAllocator()
-    result = a.realloc(a, oldSize, newSize)
+    result = a.realloc(p, oldSize, newSize)
 
 
 Pluggable GC