winemac: Fix a crash on versions of OS X prior to 10.9 which don't have the -[NSImage drawInRect:] method.

[image drawInRect:rect] is documented as being "exactly equivalent to calling
[image drawInRect:rect fromRect:NSZeroRect operation:NSCompositeSourceOver
fraction:1 respectFlipped:YES hints:nil]".  So, that's what I replace it with.
Signed-off-by: Ken Thomases <ken@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>