svga: Validate surface during copy check
What does this MR do and why?
svga: Validate surface during copy check
Fixes piglit test arb_copy_buffer-data-sync.
The test fails inconsistently because svga_buffer_surface handle is sometimes
not present at time of copy check, so the copy does not happen.
Adding a validata_host_surface() call for the surface being copied ensures the
handle is present.
Signed-off-by: Maaz Mombasawala <maaz.mombasawala@broadcom.com>
Reviewed-by: Neha Bhende <neha.bhende@broadcom.com>