msvcrt: Missing NULL checks

I've come across an interesting problem. ReactOS shares a crt library when building msvcrt and crtll. The test was fclose with a null pointer, it should crash in msvcrt not outside it. A test program is provided, just try to run or exit the program.

Test program was for System Tray testing Ref:
http://bugs.winehq.org/show_bug.cgi?id=20086