nir: fix nir_get_io_offset_src for global_atomic_swap_amd

Fixes: 354df09c88 ("nir: add global_amd to nir_get_io_offset_src/nir_get_io_index_src")

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37821>

src/compiler/nir/nir_lower_io.c

@@ -1005,7 +1005,6 @@ nir_get_io_offset_src_number(const nir_intrinsic_instr *instr)
    case nir_intrinsic_store_ssbo_intel:
    case nir_intrinsic_store_global_amd:
    case nir_intrinsic_global_atomic_amd:
-   case nir_intrinsic_global_atomic_swap_amd:
       return 2;
    case nir_intrinsic_load_ssbo_ir3:
       /* This intrinsic has 2 offsets (src1 bytes, src2 dwords), we return the
@@ -1017,6 +1016,8 @@ nir_get_io_offset_src_number(const nir_intrinsic_instr *instr)
        * dwords one for opt_offsets.
        */
       return 3;
+   case nir_intrinsic_global_atomic_swap_amd:
+      return 3;
    default:
       return -1;
    }