RDS: inc_purge() transport function unused - remove it

Signed-off-by: Andy Grover <andy.grover@oracle.com>

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

diff --cc net/rds/ib.h
Simple merge

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

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

diff --cc net/rds/iw.h
Simple merge

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

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

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

diff --cc net/rds/rds.h
Simple merge

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

diff --cc net/rds/tcp.h
Simple merge

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