ws2_32: Implement a basic synchronous TransmitFile.

[Hugh McMaster]

Hi Erich,

When checking another Wine component, I noticed build warnings for dlls/ws2_32/socket.c. 

The relevant commit is 4d081f36efefd3ccf702cacea4d20c5616cfbae1, which was your patch, so I thought I'd let you know.

socket.c: In function ‘WS2_TransmitFile’:
socket.c:2826:46: warning: ‘iosb.Information’ may be used uninitialized in this function [-Wmaybe-uninitialized]
                 wsa->write.iovec[0].iov_len  = iosb.Information;
                                              ^
socket.c:2808:25: note: ‘iosb.Information’ was declared here
         IO_STATUS_BLOCK iosb;
                         ^

Adding    iosb.Information = 0    before    status = WS2_ReadFile( wsa->file, &iosb, wsa->buffer, bytes_per_send );
fixes the warning, but I have no idea if that is correct for for ws2_32.

--
Hugh McMaster