openpgp: fix function name in comment

Change-Id: Ic788ebe311fafa0f5d9750d5f7f25fb70dc0606d
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/579175
Run-TryBot: shuang cui <imcusg@gmail.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
diff --git a/openpgp/keys_test.go b/openpgp/keys_test.go
index 0eb1a9e..9631eb6 100644
--- a/openpgp/keys_test.go
+++ b/openpgp/keys_test.go
@@ -132,7 +132,7 @@
 	}
 }
 
-// TestExternallyRevokableKey attempts to load and parse a key with a third party revocation permission.
+// TestExternallyRevocableKey attempts to load and parse a key with a third party revocation permission.
 func TestExternallyRevocableKey(t *testing.T) {
 	kring, err := ReadKeyRing(readerFromHex(subkeyUsageHex))
 	if err != nil {