7159772: instanceKlass::all_fields_count() returns incorrect total field count

Summary: Fix instanceKlass::all_fields_count() bug.
Reviewed-by: kvn, never
Contributed-by: NJiangli Zhou <jiangli.zhou@oracle.com>

src/share/vm/oops/instanceKlass.hpp

@@ -337,7 +337,7 @@ class instanceKlass: public Klass {
   int java_fields_count() const           { return (int)_java_fields_count; }
 
   // Number of fields including any injected fields
-  int all_fields_count() const            { return _fields->length() / sizeof(FieldInfo::field_slots); }
+  int all_fields_count() const            { return _fields->length() / FieldInfo::field_slots; }
 
   typeArrayOop fields() const              { return _fields; }