checked_file_impl: remove unneeded variant of open_checked_file_dma

like in integrity_checked_file_impl, we don't need a variant of
open for default file open options.

Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20171113185412.10880-1-raphaelsc@scylladb.com>

checked-file-impl.hh

@@ -130,7 +130,7 @@ inline file make_checked_file(const io_error_handler& error_handler, file f)
 future<file>
 inline open_checked_file_dma(const io_error_handler& error_handler,
                              sstring name, open_flags flags,
-                             file_open_options options)
+                             file_open_options options = {})
 {
     return do_io_check(error_handler, [&] {
         return open_file_dma(name, flags, options).then([&] (file f) {
@@ -139,17 +139,6 @@ inline open_checked_file_dma(const io_error_handler& error_handler,
     });
 }
 
-future<file>
-inline open_checked_file_dma(const io_error_handler& error_handler,
-                             sstring name, open_flags flags)
-{
-    return do_io_check(error_handler, [&] {
-        return open_file_dma(name, flags).then([&] (file f) {
-            return make_ready_future<file>(make_checked_file(error_handler, f));
-        });
-    });
-}
-
 future<file>
 inline open_checked_directory(const io_error_handler& error_handler,
                               sstring name)