RDS: Do not BUG() on error returned from ib_post_send

BUGging on a runtime error code should be avoided. This
patch also eliminates all other BUG()s that have no real
reason to exist.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/rds/ib_recv.c
Simple merge

diff --cc net/rds/ib_send.c
Simple merge

diff --cc net/rds/iw_recv.c
Simple merge

diff --cc net/rds/iw_send.c
Simple merge

diff --cc net/rds/rdma_transport.c
Simple merge