Post review fix of BUG#10969.

sql/item.h:
  Return name as LEX_STRING instead of its components.
sql/sql_yacc.yy:
  Name returned as LEX_STRING instead of its components.

sql/item.h

@@ -585,10 +585,12 @@ public:
   }
 
   /* For error printing */
-  inline void my_name(char **strp, uint *lengthp)
+  inline LEX_STRING *my_name(LEX_STRING *get_name)
   {
-    *strp= m_name.str;
-    *lengthp= m_name.length;
+    if (!get_name)
+      return &m_name;
+    (*get_name)= m_name;
+    return get_name;
   }
 
   bool is_splocal() { return 1; } /* Needed for error checking */

sql/sql_yacc.yy

@@ -4346,11 +4346,11 @@ simple_expr:
 	  {
 	    if ($3->is_splocal())
 	    {
-	      LEX_STRING name;
+	      LEX_STRING *name;
 	      Item_splocal *il= static_cast<Item_splocal *>($3);
 
-	      il->my_name(&name.str, &name.length);
-	      my_error(ER_WRONG_COLUMN_NAME, MYF(0), name.str);
+	      name= il->my_name(NULL);
+	      my_error(ER_WRONG_COLUMN_NAME, MYF(0), name->str);
 	      YYABORT;
 	    }
 	    $$= new Item_default_value($3);