Otherwise we can end up with uninitialized values, this fixes following
valgrind warning:
==71705== Uninitialised byte(s) found during client check request
==71705== at 0x73B6DB8: util_bitpack_uint (bitpack_helpers.h:55)
==71705== by 0x73B6DB8: GFX11_PIPE_CONTROL_pack (gen11_pack.h:19885)
==71705== by 0x73B6DB8: iris_emit_raw_pipe_control (iris_state.c:10022)
==71705== by 0x6F93386: iris_emit_pipe_control_write (iris_pipe_control.c:97)
==71705== by 0x6FBCCAA: iris_resource_update_indirect_color (iris_resolve.c:1241)
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Rohan Garg <rohan.garg@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30990>