crimson/os/seastore: remove multistream related codes

Current codes allow the device to allocate multiple namespace without specific policy
if the nvme device report that it is capable of mutistream functionality.
So, this commit removes the multistream related code, leaving it as a TODO.

Signed-off-by: Myoungwon Oh <[email protected]>

src/crimson/os/seastore/random_block_manager/nvme_block_device.cc

@@ -42,10 +42,7 @@ open_ertr::future<> NVMeBlockDevice::open(
         // Do identify_controller first, and then identify_namespace.
         return identify_controller(device).safe_then([this, in_path, mode](
           auto id_controller_data) {
-          support_multistream = id_controller_data.oacs.support_directives;
-          if (support_multistream) {
-            stream_id_count = WRITE_LIFE_MAX;
-          }
+	  // TODO: enable multi-stream if the nvme device supports
           awupf = id_controller_data.awupf + 1;
           return identify_namespace(device).safe_then([this, in_path, mode] (
             auto id_namespace_data) {
@@ -75,12 +72,7 @@ open_ertr::future<> NVMeBlockDevice::open_for_io(
       auto file) {
       assert(io_device.size() > stream_index_to_open);
       io_device[stream_index_to_open] = std::move(file);
-      return io_device[stream_index_to_open].fcntl(
-        F_SET_FILE_RW_HINT,
-        (uintptr_t)&stream_index_to_open).then([this](auto ret) {
-        stream_index_to_open++;
-        return seastar::now();
-      });
+      return seastar::now();
     });
   });
 }