RDMA/hns: Fix calltrace for sleeping in atomic

RDMA/hns: Fix calltrace for sleeping in atomic

We replace usleep_range that was excessively long anyway with udelay
to avoid using usleep_range function in spin_lock_bh spin region,
thereby avoiding this calltrace:

BUG: scheduling while atomic: insmod/1428/0x00000002
Modules linked in: hns-roce-hw-v2(+) hns_roce rdma_ucm rdma_cm iw_cm ib_uverbs ib_cm ib_core
CPU: 0 PID: 1428 Comm: insmod Not tainted 4.12.0-rc1-00677-g252e8fd-dirty #43
Hardware name: (null) (DT)
Call trace:
[<ffff000008089d20>] dump_backtrace+0x0/0x274
[<ffff00000808a068>] show_stack+0x20/0x28
[<ffff00000844ea58>] dump_stack+0x94/0xb4
[<ffff0000080f975c>] __schedule_bug+0x68/0x84
[<ffff000008a988d4>] __schedule+0x5fc/0x70c
[<ffff000008a98a24>] schedule+0x40/0xa4
[<ffff000008a9c6f0>] schedule_hrtimeout_range_clock+0x98/0xfc
[<ffff000008a9c788>] schedule_hrtimeout_range+0x34/0x40
[<ffff000008a9c098>] usleep_range+0x6c/0x80
[<ffff000000b9ae68>] hns_roce_cmd_send+0xe4/0x264 [hns-roce-hw-v2]
[<ffff000000b9b748>] hns_roce_cmd_query_hw_info+0x40/0x60 [hns-roce-hw-v2]
[<ffff000000b9b790>] hns_roce_v2_profile+0x28/0x668 [hns-roce-hw-v2]
[<ffff000000b6b1f4>] hns_roce_init+0x6c/0x948 [hns-roce-hw-v2]

Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>