msvcrt: Fix incorrect use of the system wctomb function.

dlls/msvcrt/file.c

@@ -3390,7 +3390,7 @@ MSVCRT_wint_t CDECL MSVCRT_fputwc(MSVCRT_wint_t wc, MSVCRT_FILE* file)
         char buf[MSVCRT_MB_LEN_MAX];
         int char_len;
 
-        char_len = wctomb(buf, mwc);
+        char_len = MSVCRT_wctomb(buf, mwc);
         if(char_len!=-1 && MSVCRT_fwrite(buf, char_len, 1, file)==1)
             ret = wc;
         else

dlls/msvcrt/msvcrt.h

@@ -945,6 +945,7 @@ int*    __cdecl  __p___mb_cur_max(void);
 unsigned int*  __cdecl __p__fmode(void);
 MSVCRT_wchar_t* __cdecl MSVCRT__wcsdup(const MSVCRT_wchar_t*);
 MSVCRT_wchar_t*** __cdecl MSVCRT___p__wenviron(void);
+INT     __cdecl MSVCRT_wctomb(char*,MSVCRT_wchar_t);
 char*   __cdecl MSVCRT__strdate(char* date);
 char*   __cdecl MSVCRT__strtime(char* date);
 int     __cdecl _setmbcp(int);