Fix #13

src/04-类型系统.md

@@ -265,7 +265,7 @@ struct MyStruct my_structs[4];
 }
 %my_structs = alloca [4 x %MyStruct]
 
-%1 = getelementptr [4 x %MyStruct], ptr %my_structs, i64 2, i32 1, i64 3
+%1 = getelementptr %MyStruct, ptr %my_structs, i64 2, i32 1, i64 3
 ```
 
 我们可以查看官方提供的[The Often Misunderstood GEP Instruction](http://llvm.org/docs/GetElementPtr.html)指南更多地了解`getelementptr`的机理。