RDMA/core: Return bool instead of int

Return bool for following internal and inline functions as their
underlying APIs return bool too.

1. cma_zero_addr()
2. cma_loopback_addr()
3. cma_any_addr()
4. ib_addr_any()
5. ib_addr_loopback()

While we are touching cma_loopback_addr(), remove extra white spaces
in it.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>