minor bug fix for WinCE in dll.c

[Tristan Savatier]

Here is a minor bug that I had to fix in order for
pthread-win32 to work on WinCE.  It has to do with
the fact that WinCE uses UNICODE (16-bit chars).

It would not hurt to include this fix the the main tree...

In dll.c:

Replace:

	GetProcAddress(_pthread_h_kernel32,
		       (LPCSTR) "TryEnterCriticalSection");

by

	GetProcAddress(_pthread_h_kernel32,
                      (const TCHAR *)TEXT("TryEnterCriticalSection"));

-t