Fix a typo in ssl.h.

Change-Id: I431c6e5b8f7de4663ba3db52f6fe0062caaf88ba
Reviewed-on: https://boringssl-review.googlesource.com/10820
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 3d705ee..46640d9 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -1653,7 +1653,7 @@
 /* SSL_SESS_CACHE_SERVER enables session caching for a server. */
 #define SSL_SESS_CACHE_SERVER 0x0002
 
-/* SSL_SESS_CACHE_SERVER enables session caching for both client and server. */
+/* SSL_SESS_CACHE_BOTH enables session caching for both client and server. */
 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
 
 /* SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling