net/smc: check for valid ib_client_data

net/smc: check for valid ib_client_data

BugLink: https://bugs.launchpad.net/bugs/1867903
commit a2f2ef4a54c0d97aa6a8386f4ff23f36ebb488cf upstream.

In smc_ib_remove_dev() check if the provided ib device was actually
initialized for SMC before.

Reported-by: syzbot+84484ccebdd4e5451d91@syzkaller.appspotmail.com
Fixes: a4cf0443c414 ("smc: introduce SMC as an IB-client")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>