client: Use read preparation API in wl_display_dispatch_queue()
client: Use read preparation API in wl_display_dispatch_queue()

Instead of doing things that do the equivalent of using
wl_display_prepare_read() and friends, just use the public API. The
only semantical difference is that we will now unlock and lock the mutex
more times compared to before.

Signed-off-by: Jonas Ådahl <67dcd8a17e758192e0cbb577ce1d62cc7da6cf49@gmail.com>
Reviewed-by: Daniel Stone <62e7e355d5d8400fa8384448796af0bf6be4ffae@collabora.com>

sir-murray/wayland,sir-murray/wayland,sir-murray/wayland,mchalupa/wayland,mchalupa/wayland,mchalupa/wayland