Include the extension in the error in ssl_parse_extensions

This mirrors the callback-based system. If we get an unsolicited
extension, it's nice to say which it was.

Also fix one of the existing ones to remove what seems to have been a
stray colon.

Change-Id: I2a796ea008823fc749eebc3d2d22b94562329b6b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/75427
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>

ssl/extensions.cc

diff --git a/ssl/extensions.cc b/ssl/extensions.cc
index df914c8..eb15914 100644
--- a/ssl/extensions.cc
+++ b/ssl/extensions.cc
@@ -3667,7 +3667,7 @@
     if (!(hs->extensions.sent & (1u << ext_index))) {
       // If the extension was never sent then it is illegal.
       OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
-      ERR_add_error_dataf("extension :%u", (unsigned)type);
+      ERR_add_error_dataf("extension %u", (unsigned)type);
       *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
       return false;
     }

ssl/handshake.cc

diff --git a/ssl/handshake.cc b/ssl/handshake.cc
index 84df6f0..18e9c3c 100644
--- a/ssl/handshake.cc
+++ b/ssl/handshake.cc
@@ -198,6 +198,7 @@
         continue;
       }
       OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_EXTENSION);
+      ERR_add_error_dataf("extension %u", unsigned{type});
       *out_alert = SSL_AD_UNSUPPORTED_EXTENSION;
       return false;
     }