cmd/doc: fix inconsistent receiver name

The ToText method of Package is the only one with a receiver declared
'p'; all the rest have 'pkg'. Fix it to be consistent.

Change-Id: I2b47c719f4f6f8d87336316b7f80deb1b49e17dc
GitHub-Last-Rev: 7d273b4
GitHub-Pull-Request: #64912
Reviewed-on: https://go-review.googlesource.com/c/go/+/553335
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: qiulaidongfeng <2645477756@qq.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

src/cmd/doc/pkg.go

@@ -43,9 +43,9 @@ type Package struct {
 	buf         pkgBuffer
 }
 
-func (p *Package) ToText(w io.Writer, text, prefix, codePrefix string) {
-	d := p.doc.Parser().Parse(text)
-	pr := p.doc.Printer()
+func (pkg *Package) ToText(w io.Writer, text, prefix, codePrefix string) {
+	d := pkg.doc.Parser().Parse(text)
+	pr := pkg.doc.Printer()
 	pr.TextPrefix = prefix
 	pr.TextCodePrefix = codePrefix
 	w.Write(pr.Text(d))