Iron out /WX errors in VC-WIN32.

Reviewed-by: NRichard Levitte <levitte@openssl.org>

test/siphash_internal_test.c

@@ -235,10 +235,10 @@ static int test_siphash(int idx)
 
     /* key and in data are 00 01 02 ... */
     for (i = 0; i < sizeof(key); i++)
-        key[i] = i;
+        key[i] = (unsigned char)i;
 
     for (i = 0; i < inlen; i++)
-        in[i] = i;
+        in[i] = (unsigned char)i;
 
     if (!TEST_true(SipHash_Init(&siphash, key, expectedlen, 0, 0)))
         return 0;

test/sslapitest.c

@@ -1819,7 +1819,7 @@ static int early_data_skip_helper(int hrr, int idx)
          * time. It could be any value as long as it is not within tolerance.
          * This should mean the ticket is rejected.
          */
-        if (!TEST_true(SSL_SESSION_set_time(sess, time(NULL) - 20)))
+        if (!TEST_true(SSL_SESSION_set_time(sess, (long)(time(NULL) - 20))))
             goto end;
     }
 
@@ -1984,7 +1984,7 @@ static int alpn_select_cb(SSL *ssl, const unsigned char **out,
 
     for (prot = in; prot < in + inlen; prot += protlen) {
         protlen = *prot++;
-        if (in + inlen - prot < protlen)
+        if (in + inlen < prot + protlen)
             return SSL_TLSEXT_ERR_NOACK;
 
         if (protlen == strlen(servalpn)

test/x509_internal_test.c

@@ -35,7 +35,7 @@
 # pragma names restore
 #endif
 
-static int test_standard_exts()
+static int test_standard_exts(void)
 {
     size_t i;
     int prev = -1, good = 1;