Update link_name=... -> link(name=...

src/doc/guide-ffi.md

@@ -520,7 +520,7 @@ conventions. Rust provides a way to tell the compiler which convention to use:
 
 ~~~~
 #[cfg(target_os = "win32", target_arch = "x86")]
-#[link_name = "kernel32"]
+#[link(name = "kernel32")]
 extern "stdcall" {
     fn SetEnvironmentVariableA(n: *u8, v: *u8) -> std::libc::c_int;
 }