gstreamer: Prevent integer overflow in delay computation
gstreamer: Prevent integer overflow in delay computation

The partial expression "MSEC_PER_SEC * size * 8" can overflow if
size is 536870 or more. This as the operation is done using
32 bit unsigned integers. Being the size potentially double of
a compressed frame size the limit can be easily reached.
As get_average_frame_size already return a 64 bit use 64 bit
even for the size to avoid the integer overflow.

Signed-off-by: Frediano Ziglio <55d48b080b2e443e395cde84d2c83b135a4ff48e@redhat.com>
Acked-by: Francois Gouget <6b915da68578f6eb004fe99432b967565fc9be8f@codeweavers.com>

fgouget/spice,fgouget/spice,fgouget/spice,fgouget/spice