Coverity build fixes.

Like every other toolchain I've tried, my Coverity scanning build has
its share of random objections to parts of my Windows API type-
checking system. I do wonder if that bright idea was worth the hassle
- but it would probably cost all the annoyance all over again to back
out now...

windows/winmisc.c

@@ -177,9 +177,11 @@ void dll_hijacking_protection(void)
 
     if (!kernel32_module) {
         kernel32_module = load_system32_dll("kernel32.dll");
-#if defined _MSC_VER && _MSC_VER < 1900
-        /* For older Visual Studio, this function isn't available in
-         * the header files to type-check */
+#if (defined _MSC_VER && _MSC_VER < 1900) || defined COVERITY
+        /* For older Visual Studio, and also for the system I
+         * currently use for Coveritying the Windows code, this
+         * function isn't available in the header files to
+         * type-check */
         GET_WINDOWS_FUNCTION_NO_TYPECHECK(
             kernel32_module, SetDefaultDllDirectories);
 #else