LU-17149 tbf: nrs_tbf_id_cli_set should not modify the fmt

LU-17149 tbf: nrs_tbf_id_cli_set should not modify the fmt

nrs_tbf_id_cli_set() needs to parse LDLM_ENQUEUE request to find
uid/gid.

It calls req_capsule_extend() that change the request format (rc_fmt).
If rc_fmt was not null, the function will not restore the initial
request format.

The following crash will occur the 2sd time that nrs_tbf_id_cli_set()
is called (1st: o_cli_find(), 2sd: o_cli_init()):

LustreError: 8949:0:(req_capsule_extend())
ASSERTION( fmt->rf_fields[i].nr >= old->rf_fields[i].nr ) failed:
Call Trace TBD:
[<0>] libcfs_call_trace+0x6f/0xa0 [libcfs]
[<0>] lbug_with_loc+0x3f/0x70 [libcfs]
[<0>] req_capsule_extend+0x174/0x1b0 [ptlrpc]
[<0>] nrs_tbf_id_cli_set+0x1ee/0x2a0 [ptlrpc]
[<0>] nrs_tbf_generic_cli_init+0x50/0x180 [ptlrpc]
[<0>] nrs_tbf_res_get+0x1fe/0x430 [ptlrpc]
[<0>] nrs_resource_get+0x6c/0xe0 [ptlrpc]
[<0>] nrs_resource_get_safe+0x87/0xe0 [ptlrpc]
[<0>] ptlrpc_nrs_req_initialize+0x58/0xb0 [ptlrpc]
[<0>] ptlrpc_server_request_add+0x248/0xa20 [ptlrpc]
[<0>] ptlrpc_server_handle_req_in+0x36a/0x8c0 [ptlrpc]
[<0>] ptlrpc_main+0xb97/0x1530 [ptlrpc]
[<0>] kthread+0x134/0x150
[<0>] ret_from_fork+0x1f/0x40

Test-Parameters: testlist=sanityn env=ONLY=77
Test-Parameters: testlist=sanityn env=ONLY=77
Test-Parameters: testlist=sanityn env=ONLY=77
Signed-off-by: Etienne AUJAMES <eaujames@ddn.com>
Change-Id: Ia762936262e8cde891ae2a9daf4ce691c6a6f616
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52528
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Feng Lei <flei@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>