go.crypto/openpgp/packet: fix comment typo.

Thanks to Matt Goodall for pointing this out.

Change-Id: I30225299de2a6aba381f38bd753672c1137c3d5f
Reviewed-on: https://go-review.googlesource.com/11873
Reviewed-by: Adam Langley <agl@golang.org>

openpgp/packet/public_key.go

@@ -193,7 +193,7 @@ func NewRSAPublicKey(creationTime time.Time, pub *rsa.PublicKey) *PublicKey {
 	return pk
 }
 
-// NewDSAPublicKey returns a PublicKey that wraps the given rsa.PublicKey.
+// NewDSAPublicKey returns a PublicKey that wraps the given dsa.PublicKey.
 func NewDSAPublicKey(creationTime time.Time, pub *dsa.PublicKey) *PublicKey {
 	pk := &PublicKey{
 		CreationTime: creationTime,