RDMA/uverbs: Make write() handlers return 0 on success

Currently they return the command length, while all other handlers return
0. This makes the write path closer to the write_ex and ioctl path.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
7 files changed