[x/blog] _content: fix broken links in cgo article

The correct links to sections on cmd/go page are prefixed with "hdr-".

Change-Id: I8301a8f93c2a6ebbc3d67a9a82c809e776976922
Reviewed-on: https://go-review.googlesource.com/c/blog/+/319470
Trust: Alberto Donizetti <alb.donizetti@gmail.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
X-Blog-Commit: 594fa988c67b77baa1b04aa1ae57dc507f2f8045
diff --git a/blog/_content/cgo.article b/blog/_content/cgo.article
index 0697395..66988fa 100644
--- a/blog/_content/cgo.article
+++ b/blog/_content/cgo.article
@@ -136,8 +136,8 @@
 
 ## Building cgo packages
 
-To build cgo packages, just use [`go build`](https://golang.org/cmd/go/#Compile_packages_and_dependencies)
-or [`go install`](https://golang.org/cmd/go/#Compile_and_install_packages_and_dependencies) as usual.
+To build cgo packages, just use [`go build`](https://golang.org/cmd/go/#hdr-Compile_packages_and_dependencies)
+or [`go install`](https://golang.org/cmd/go/#hdr-Compile_and_install_packages_and_dependencies) as usual.
 The go tool recognizes the special `"C"` import and automatically uses cgo for those files.
 
 ## More cgo resources