Fix SSL_write doc comment

Change-Id: Icb01cd3ff88eb3fa8a7d7a1e9ead568ba20eb748
Reviewed-on: https://boringssl-review.googlesource.com/13965
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index e38e23c..e284068 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -355,7 +355,7 @@
 
 /* SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
  * any pending handshakes, including renegotiations when enabled. On success, it
- * returns the number of bytes read. Otherwise, it returns <= 0. The caller
+ * returns the number of bytes written. Otherwise, it returns <= 0. The caller
  * should pass the value into |SSL_get_error| to determine how to proceed.
  *
  * In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that