stp_utrace: disable IRQs when holding the bucket spin lock

stp_utrace: disable IRQs when holding the bucket spin lock

This lock can be acquired from inside an IRQ, leading to a deadlock:

WARNING: inconsistent lock state
4.14.35-1902.6.6.el7uek.x86_64.debug #2 Tainted: G           OE
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
sh/15779 [HC1[1]:SC0[0]:HE0:SE1] takes:
 (&(lock)->rlock#3){?.+.}, at: [<ffffffffc0c080b0>] _stp_mempool_alloc+0x35/0xab [orxray_lj_lua_fgraph_XXXXXXX]
{HARDIRQ-ON-W} state was registered at:
  lock_acquire+0xe0/0x238
  _raw_spin_lock+0x3d/0x7a
  utrace_task_alloc+0xa4/0xe3 [orxray_lj_lua_fgraph_XXXXXXX]
  utrace_attach_task+0x136/0x194 [orxray_lj_lua_fgraph_XXXXXXX]
  __stp_utrace_attach+0x57/0x216 [orxray_lj_lua_fgraph_XXXXXXX]
  stap_start_task_finder+0x12e/0x33f [orxray_lj_lua_fgraph_XXXXXXX]
  systemtap_module_init+0x114d/0x11f0 [orxray_lj_lua_fgraph_XXXXXXX]
  _stp_handle_start+0xea/0x1c5 [orxray_lj_lua_fgraph_XXXXXXX]
  _stp_ctl_write_cmd+0x28d/0x2d1 [orxray_lj_lua_fgraph_XXXXXXX]
  full_proxy_write+0x67/0xbb
  __vfs_write+0x3a/0x170
  vfs_write+0xc7/0x1c0
  SyS_write+0x58/0xbf
  do_syscall_64+0x7e/0x22c
  entry_SYSCALL_64_after_hwframe+0x16e/0x0
irq event stamp: 9454
hardirqs last  enabled at (9453): [<ffffffffa696c960>] _raw_write_unlock_irqrestore+0x40/0x67
hardirqs last disabled at (9454): [<ffffffffa6a05417>] apic_timer_interrupt+0x1c7/0x1d1
softirqs last  enabled at (9202): [<ffffffffa6c00361>] __do_softirq+0x361/0x4e5
softirqs last disabled at (9195): [<ffffffffa60aeb76>] irq_exit+0xf6/0x102

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(lock)->rlock#3);
  <Interrupt>
    lock(&(lock)->rlock#3);

 *** DEADLOCK ***

no locks held by sh/15779.

stack backtrace:
CPU: 16 PID: 15779 Comm: sh Tainted: G           OE   4.14.35-1902.6.6.el7uek.x86_64.debug #2
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 <IRQ>
 dump_stack+0x81/0xb6
 print_usage_bug+0x1fc/0x20d
 ? check_usage_backwards+0x130/0x12b
 mark_lock+0x1f8/0x27b
 __lock_acquire+0x6e7/0x165a
 ? sched_clock_local+0x18/0x81
 ? perf_swevent_hrtimer+0x136/0x151
 lock_acquire+0xe0/0x238
 ? _stp_mempool_alloc+0x35/0xab [orxray_lj_lua_fgraph_XXXXXXX]
 _raw_spin_lock_irqsave+0x55/0x97
 ? _stp_mempool_alloc+0x35/0xab [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_mempool_alloc+0x35/0xab [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_ctl_get_buffer+0x69/0x215 [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_ctl_send+0x4e/0x169 [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_vlog+0xac/0x143 [orxray_lj_lua_fgraph_XXXXXXX]
 ? _stp_utrace_probe_cb+0xa4/0xa4 [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_warn+0x6a/0x88 [orxray_lj_lua_fgraph_XXXXXXX]
 function___global_warn__overload_0+0x60/0xac [orxray_lj_lua_fgraph_XXXXXXX]
 probe_67+0xce/0x10e [orxray_lj_lua_fgraph_XXXXXXX]
 _stp_hrtimer_notify_function+0x2db/0x55f [orxray_lj_lua_fgraph_XXXXXXX]
 __hrtimer_run_queues+0x132/0x5c5
 hrtimer_interrupt+0xb7/0x1ca
 smp_apic_timer_interrupt+0xa5/0x35a
 apic_timer_interrupt+0x1cc/0x1d1
 </IRQ>