radv/gfx10: Move NGG output handling outside of giant if-statement.

radv/gfx10: Move NGG output handling outside of giant if-statement.

In merged shaders we put a big if around each shader, so both stages
can have a different number of threads. However, the NGG output code
still needs to run if the first shader is not executed.

This can happen when there are more gs threads than vs/es threads, or
when there are 0 es/vs threads (why? no clue).

Fixes: ee21bd7440c "radv/gfx10: implement NGG support (VS only)"
Reviewed-by: Dave Airlie <airlied@redhat.com>