Fix code style

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c4f8bd3..a7735c3 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5260,7 +5260,8 @@
              SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT) | \
          (SSL_SERIALIZED_SESSION_CONFIG_ETM << SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT) | \
          (SSL_SERIALIZED_SESSION_CONFIG_TICKET << SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT) | \
-         (SSL_SERIALIZED_SESSION_CONFIG_KEEP_PEER_CRT << SSL_SERIALIZED_SESSION_CONFIG_KEEP_PEER_CRT_BIT)))
+         (SSL_SERIALIZED_SESSION_CONFIG_KEEP_PEER_CRT << \
+             SSL_SERIALIZED_SESSION_CONFIG_KEEP_PEER_CRT_BIT)))
 
 static const unsigned char ssl_serialized_session_header[] = {
     MBEDTLS_VERSION_MAJOR,