Check null pointer before fclose (#586)

* Check null pointer before fclose, because fclose(NULL) will lead to undefined behavior

* Update main.cpp

Cast to one code style

* Update main.cpp

Remove redundant ==

src/terminal/parser/ft_fuzzwrapper/main.cpp

@@ -70,7 +70,10 @@ int __cdecl wmain(int argc, wchar_t* argv[])
             fGotChar = GetChar(&wch);
         }
 
-        fclose(hFile);
+        if (hFile)
+        {
+            fclose(hFile);
+        }
         wprintf(L"Done.\r\n");
     }