radv:  Fix uninitialized warning.

For es_vgpr_comp_cnt.

Fixes: 795adbbadd4 "radv/gfx10: Add pipeline state support for tess."
Reviewed-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
diff --git a/src/amd/vulkan/radv_shader.c b/src/amd/vulkan/radv_shader.c
index 3b00bf8..4262dae 100644
--- a/src/amd/vulkan/radv_shader.c
+++ b/src/amd/vulkan/radv_shader.c
@@ -810,7 +810,8 @@
 		} else if (es_stage == MESA_SHADER_TESS_EVAL) {
 			bool enable_prim_id = info->tes.export_prim_id || info->info.uses_prim_id;
 			es_vgpr_comp_cnt = enable_prim_id ? 3 : 2;
-		}
+		} else
+			unreachable("Unexpected ES shader stage");
 
 		bool tes_triangles = stage == MESA_SHADER_TESS_EVAL &&
 			info->tes.primitive_mode >= 4; /* GL_TRIANGLES */