egl: make eglSwapBuffers* a no-op for !window surfaces

Analogous to the previous commit - the spec says the function is a
no-op when a pbuffer or pixmap surface is used.

Cc: samiuddi <sami.uddin.mohammad@intel.com>
Cc: Erik Faye-Lund <kusmabite@gmail.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
(cherry picked from commit 8f66743c)