infiniband: hfi1: drop crazy DEBUGFS_SEQ_FILE_CREATE() macro

The macro was just making things harder to follow, and audit, so remove
it and call debugfs_create_file() directly.  Also, the macro did not
need to warn about the call failing as no one should ever care about any
debugfs functions failing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>