psdk: Fix PFN_PROVUI_CALL declaration in wintrust.h

Created an attachment (id=7602)
Fix for this bug.

PFN_PROVUI_CALL has not a CALLBACK modifier.
Correct declaration can be found here:

http://msdn.microsoft.com/en-us/library/windows/desktop/aa381459%28v=vs.85%29.aspx

The attached patch will fix wintrust.h and it will sync the file at the same level of wine-1.5.2

Sincerely,

Carlo Bramini