Fixes Piglit test "swapbuffersmsc-return swap_interval 0".
Ensure that *swap_target gets initialized on any 'return Success' path,
even if the swap request can't be completed by the driver and the server
falls back to a simple blit. That path can also be triggered by setting
swap_interval to 0, which disables sync to vertical retrace.
We originally found this bug because for some reason SDL2 automatically
sets swap_interval to 0, when we were trying to test OML_sync_control in
an SDL2 test application. We then discovered that the above-mentioned
Piglit test has been failing for the same reason since it was
introduced.
Signed-off-by: Jamey Sharp <jamey@minilop.net>
Signed-off-by: Theo Hill <Theo0x48@gmail.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Keith Packard <keithp@keithp.com>