i965: Make emit_urb_writes() only set EOT for the VS.
i965: Make emit_urb_writes() only set EOT for the VS.

The GS will emit a bunch of vertices, and we don't want to do an EOT
prematurely.  We'll emit GS_OPCODE_THREAD_END when we want to terminate
the thread.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Kristian Høgsberg <ca9b5b1e27d4fa7f4ba6848bdd08ca52cfd6330c@bitplanet.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler