Satisfy golint.

Errors are supposed to be fragments that go into sentences, rather than
sentences themselves.

Change-Id: I6569fce25535475162c85e7b0db7eeb62c93febd
Reviewed-on: https://boringssl-review.googlesource.com/c/33324
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>

ssl/test/runner/handshake_client.go

diff --git a/ssl/test/runner/handshake_client.go b/ssl/test/runner/handshake_client.go
index d25bbab..ab1f4dd 100644
--- a/ssl/test/runner/handshake_client.go
+++ b/ssl/test/runner/handshake_client.go
@@ -59,12 +59,15 @@
 	hello.random = newHello.random
 	hello.sessionId = newHello.sessionId
 
-	// Replace |ret|'s key shares with those of |hello|.
+	// Replace |ret|'s key shares with those of |hello|. For simplicity, we
+	// require their lengths match, which is satisfied by matching the
+	// DefaultCurves setting to the selection in the replacement
+	// ClientHello.
 	bb := newByteBuilder()
 	hello.marshalKeyShares(bb)
 	keyShares := bb.finish()
 	if len(keyShares) != len(newHello.keySharesRaw) {
-		return nil, errors.New("tls: ClientHello key share lengths did not match. Reconfigure DefaultCurves.")
+		return nil, errors.New("tls: ClientHello key share length is inconsistent with DefaultCurves setting")
 	}
 	// |newHello.keySharesRaw| aliases |ret|.
 	copy(newHello.keySharesRaw, keyShares)