Derek Foreman authored Sep 30, 2016 and Daniel Stone committed Nov 16, 2016

If only the source of a viewport is set, the width and height must
be integer or the protocol mandates that the compositor generate an
error.  This is because using only the source is a crop, and the
width and height become the surface size - all surface sizes must
be integer.

Weston was fixed to generate this error in bb32ccc0

, however the
test app continued to use fractional co-ordinates when run as
weston-scaler -s  (which only sets the viewport source)

This leaves fractional width/height for the other cases, but uses
integer for the crop-only mode.  The descriptions in the help text
are still accurate with this change, but weston-scaler -s no longer
exits with an error.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>