RDMA/srpt: Support specifying the srpt_service_guid parameter

In the Linux kernel, the following vulnerability has been resolved:

RDMA/srpt: Support specifying the srpt_service_guid parameter

Make loading ib_srpt with this parameter set work. The current behavior is

that setting that parameter while loading the ib_srpt kernel module

triggers the following kernel crash:

BUG: kernel NULL pointer dereference, address: 0000000000000000

Call Trace:

<TASK>

parse_one+0x18c/0x1d0

parse_args+0xe1/0x230

load_module+0x8de/0xa60

init_module_from_file+0x8b/0xd0

idempotent_init_module+0x181/0x240

__x64_sys_finit_module+0x5a/0xb0

do_syscall_64+0x5f/0xe0

entry_SYSCALL_64_after_hwframe+0x6e/0x76