go/packages: rename Illtyped to IllTyped in docs

Fix the field name in docs to have the correct case, as seen at
https://godoc.org/golang.org/x/tools/go/packages#Package.IllTyped.

Change-Id: I3184c2fc5f9c4641a61dbd2af6a11309e9f284ea
Reviewed-on: https://go-review.googlesource.com/c/157797
Reviewed-by: Michael Matloob <matloob@golang.org>
diff --git a/go/packages/packages.go b/go/packages/packages.go
index 15927f1..e69ddfc 100644
--- a/go/packages/packages.go
+++ b/go/packages/packages.go
@@ -52,7 +52,7 @@
 
 	// LoadAllSyntax adds typed syntax trees for the packages matching the patterns
 	// and all dependencies.
-	// Package fields added: Types, Fset, Illtyped, Syntax, and TypesInfo,
+	// Package fields added: Types, Fset, IllTyped, Syntax, and TypesInfo,
 	// for all packages in the import graph.
 	LoadAllSyntax
 )