Resolve warnings in VC-WIN32 build, which allows to add /WX.

It's argued that /WX allows to keep better focus on new code, which
motivates its comeback...

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4721)
diff --git a/test/ct_test.c b/test/ct_test.c
index 45dd2e9..21f1868 100644
--- a/test/ct_test.c
+++ b/test/ct_test.c
@@ -501,10 +501,11 @@
     int success = 0;
     CT_POLICY_EVAL_CTX *ct_policy_ctx = CT_POLICY_EVAL_CTX_new();
     const time_t default_time = CT_POLICY_EVAL_CTX_get_time(ct_policy_ctx) /
-            1000;
+                                1000;
     const time_t time_tolerance = 600;  /* 10 minutes */
 
-    if (!TEST_uint_le(fabs(difftime(time(NULL), default_time)), time_tolerance))
+    if (!TEST_uint_le((unsigned int)fabs(difftime(time(NULL), default_time)),
+                      (unsigned int)time_tolerance))
         goto end;
 
     success = 1;