hfi1: get rid of redundant debugfs_file_{get,put}()

All files in question are created via debugfs_create_file(), so
exclusion with removals is provided by debugfs wrappers; as the matter
of fact, hfi1-private wrappers had been redundant at least since 2017...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20250702211508.GB3406663@ZenIV


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>