Remove redundant statement from x509_get_current_time
diff --git a/library/x509.c b/library/x509.c
index 15c0123..c17697b 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -897,8 +897,6 @@
     mbedtls_time_t tt;
     int ret = 0;
 
-    (void)tm_buf;
-
     tt = mbedtls_time( NULL );
     lt = mbedtls_platform_gmtime( &tt, &tm_buf );