hw/cxl: drop pointless memory_region_transaction_guards

Not clear what intent was here, but probably based on a misunderstanding
of what these guards are for.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20230421135906.3515-2-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/cxl/cxl-component-utils.c

@@ -47,14 +47,12 @@ static void dumb_hdm_handler(CXLComponentState *cxl_cstate, hwaddr offset,
         break;
     }
 
-    memory_region_transaction_begin();
     stl_le_p((uint8_t *)cache_mem + offset, value);
     if (should_commit) {
         ARRAY_FIELD_DP32(cache_mem, CXL_HDM_DECODER0_CTRL, COMMIT, 0);
         ARRAY_FIELD_DP32(cache_mem, CXL_HDM_DECODER0_CTRL, ERR, 0);
         ARRAY_FIELD_DP32(cache_mem, CXL_HDM_DECODER0_CTRL, COMMITTED, 1);
     }
-    memory_region_transaction_commit();
 }
 
 static void cxl_cache_mem_write_reg(void *opaque, hwaddr offset, uint64_t value,