RDMA/qedr: Fix qp structure memory leak

The qedr_qp structure wasn't freed when the protocol was RoCE.  kmemleak
output when running basic RoCE scenario.

unreferenced object 0xffff927ad7e22c00 (size 1024):
  comm "ib_send_bw", pid 7082, jiffies 4384133693 (age 274.698s)
  hex dump (first 32 bytes):
    00 b0 cd a2 79 92 ff ff 00 3f a1 a2 79 92 ff ff  ....y....?..y...
    00 ee 5c dd 80 92 ff ff 00 f6 5c dd 80 92 ff ff  ..\.......\.....
  backtrace:
    [<00000000b2ba0f35>] qedr_create_qp+0xb3/0x6c0 [qedr]
    [<00000000e85a43dd>] ib_uverbs_handler_UVERBS_METHOD_QP_CREATE+0x555/0xad0 [ib_uverbs]
    [<00000000fee4d029>] ib_uverbs_cmd_verbs+0xa5a/0xb80 [ib_uverbs]
    [<000000005d622660>] ib_uverbs_ioctl+0xa4/0x110 [ib_uverbs]
    [<00000000eb4cdc71>] ksys_ioctl+0x87/0xc0
    [<00000000abe6b23a>] __x64_sys_ioctl+0x16/0x20
    [<0000000046e7cef4>] do_syscall_64+0x4d/0x90
    [<00000000c6948f76>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 1212767e23 ("qedr: Add wrapping generic structure for qpidr and adjust idr routines.")
Link: https://lore.kernel.org/r/20200902165741.8355-2-michal.kalderon@marvell.com
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/hw/qedr/verbs.c

@@ -2744,6 +2744,8 @@ int qedr_destroy_qp(struct ib_qp *ibqp, struct ib_udata *udata)
 
 	if (rdma_protocol_iwarp(&dev->ibdev, 1))
 		qedr_iw_qp_rem_ref(&qp->ibqp);
+	else
+		kfree(qp);
 
 	return 0;
 }