cmd/go: fix typo

Fixes #3619.

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/6211055

src/cmd/go/doc.go

@@ -546,7 +546,7 @@ in those files and ignoring any other files in the directory.
 
 Remote import path syntax
 
-An import path (see 'go help importpath') denotes a package
+An import path (see 'go help packages') denotes a package
 stored in the local file system.  Certain import paths also
 describe how to obtain the source code for the package using
 a revision control system.

src/cmd/go/help.go

@@ -138,7 +138,7 @@ The meta tag has the form:
 
 	<meta name="go-import" content="import-prefix vcs repo-root">
 
-The import-prefix is the import path correponding to the repository
+The import-prefix is the import path corresponding to the repository
 root. It must be a prefix or an exact match of the package being
 fetched with "go get". If it's not an exact match, another http
 request is made at the prefix to verify the <meta> tags match.

src/cmd/go/main.go

@@ -144,7 +144,7 @@ func main() {
 		}
 	}
 
-	fmt.Fprintf(os.Stderr, "go: unknown subcommand %#q\nRun 'go help' for usage.\n", args[0])
+	fmt.Fprintf(os.Stderr, "go: unknown subcommand %q\nRun 'go help' for usage.\n", args[0])
 	setExitStatus(2)
 	exit()
 }