r600g: remove unused variables to fix compile warnings

src/gallium/drivers/r600/evergreen_compute.c

@@ -479,8 +479,6 @@ static void evergreen_launch_grid(
 		uint32_t pc, const void *input)
 {
 	struct r600_context *ctx = (struct r600_context *)ctx_;
-	struct r600_pipe_compute *shader = ctx->cs_shader_state.shader;
-	void *p;
 
 	COMPUTE_DBG("*** evergreen_launch_grid: pc = %u\n", pc);
 

src/gallium/drivers/r600/evergreen_compute_internal.c

@@ -294,8 +294,6 @@ void evergreen_set_rat(
 	pipe->ctx->compute_cb_target_mask |= (0xf << (id * 4));
 
 	surf = (struct r600_surface*)pipe->ctx->framebuffer.state.cbufs[id];
-
-	struct radeon_surface *rsurf = &((struct r600_texture*)surf->base.texture)->surface;
 	evergreen_init_color_surface_rat(rctx, surf);
 }