Merged common statements [Bug #16242]

class.c

@@ -825,20 +825,14 @@ VALUE
 rb_include_class_new(VALUE module, VALUE super)
 {
     VALUE klass = class_alloc(T_ICLASS, rb_cClass);
-    RCLASS_SET_ORIGIN(klass, klass);
 
     RCLASS_M_TBL(OBJ_WB_UNPROTECT(klass)) =
       RCLASS_M_TBL(OBJ_WB_UNPROTECT(module)); /* TODO: unprotected? */
 
+    RCLASS_SET_ORIGIN(klass, module == RCLASS_ORIGIN(module) ? klass : RCLASS_ORIGIN(module));
     if (BUILTIN_TYPE(module) == T_ICLASS) {
-        if (module != RCLASS_ORIGIN(module)) {
-            RCLASS_SET_ORIGIN(klass, RCLASS_ORIGIN(module));
-        }
 	module = RBASIC(module)->klass;
     }
-    else if (module != RCLASS_ORIGIN(module)) {
-        RCLASS_SET_ORIGIN(klass, RCLASS_ORIGIN(module));
-    }
     if (!RCLASS_IV_TBL(module)) {
 	RCLASS_IV_TBL(module) = st_init_numtable();
     }