RDMA/qedr: Return success when not changing QP state

[ Upstream commit 865cea40b69741c3da2574176876463233b2b67c ]

If the user is requesting us to change the QP state to the same state
that it is already in, return success instead of failure.

Signed-off-by: Ram Amrani <Ram.Amrani@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>