gallivm: add missing break

Fixes: 26c5ae80f0b5 ("llvmpipe: enable ARB_shader_group_vote")

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5714>
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_nir.c b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
index 2c4135c..09b1068 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_nir.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_nir.c
@@ -1496,6 +1496,7 @@
    case nir_intrinsic_global_atomic_exchange:
    case nir_intrinsic_global_atomic_comp_swap:
       visit_global_atomic(bld_base, instr, result);
+      break;
    case nir_intrinsic_vote_all:
    case nir_intrinsic_vote_any:
    case nir_intrinsic_vote_ieq: