Fix dodgy printf calls

Pacify `clang -Wformat-pedantic`.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 454b1eb..9d8857d 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -3127,8 +3127,8 @@
                                    MBEDTLS_PRINTF_SIZET " from %p to %p (buf=%p len=%"
                                    MBEDTLS_PRINTF_SIZET ")",
                                    ssl->in_msglen,
-                                   ssl->in_msg, payload_end,
-                                   ssl->in_buf, in_buf_len));
+                                   (void *) ssl->in_msg, (void *) payload_end,
+                                   (void *) ssl->in_buf, in_buf_len));
             return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
         }
         memmove(payload_end, ssl->in_msg, ssl->in_msglen);