Loading rcutorture as a module (as opposed to building it directly into
the kernel) results in the following splat:

[Wed Apr 16 15:29:33 2014] BUG: unable to handle kernel paging request at ffffffffa0003000
[Wed Apr 16 15:29:33 2014] IP: [<ffffffffa0003000>] 0xffffffffa0003000
[Wed Apr 16 15:29:33 2014] PGD 1c0f067 PUD 1c10063 PMD 378a6067 PTE 0
[Wed Apr 16 15:29:33 2014] Oops: 0010 [#1] SMP
[Wed Apr 16 15:29:33 2014] Modules linked in: rcutorture(+) torture
[Wed Apr 16 15:29:33 2014] CPU: 0 PID: 4257 Comm: modprobe Not tainted 3.15.0-rc1 #10
[Wed Apr 16 15:29:33 2014] Hardware name: innotek GmbH VirtualBox, BIOS VirtualBox 12/01/2006
[Wed Apr 16 15:29:33 2014] task: ffff8800db1e88d0 ti: ffff8800db25c000 task.ti: ffff8800db25c000
[Wed Apr 16 15:29:33 2014] RIP: 0010:[<ffffffffa0003000>]  [<ffffffffa0003000>] 0xffffffffa0003000
[Wed Apr 16 15:29:33 2014] RSP: 0018:ffff8800db25dca0  EFLAGS: 00010282
[Wed Apr 16 15:29:33 2014] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[Wed Apr 16 15:29:33 2014] RDX: ffffffffa00090a8 RSI: 0000000000000001 RDI: ffffffffa0008337
[Wed Apr 16 15:29:33 2014] RBP: ffff8800db25dd50 R08: 0000000000000000 R09: 0000000000000000
[Wed Apr 16 15:29:33 2014] R10: ffffea000357b680 R11: ffffffff8113257a R12: ffffffffa000d000
[Wed Apr 16 15:29:33 2014] R13: ffffffffa00094c0 R14: ffffffffa0009510 R15: 0000000000000001
[Wed Apr 16 15:29:33 2014] FS:  00007fee30ce5700(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
[Wed Apr 16 15:29:33 2014] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[Wed Apr 16 15:29:33 2014] CR2: ffffffffa0003000 CR3: 00000000d5eb1000 CR4: 00000000000006f0
[Wed Apr 16 15:29:33 2014] Stack:
[Wed Apr 16 15:29:33 2014]  ffffffffa000d02c 0000000000000000 ffff88021700d400 0000000000000000
[Wed Apr 16 15:29:33 2014]  ffff8800db25dd40 ffffffff81647951 ffff8802162bd000 ffff88021541846c
[Wed Apr 16 15:29:33 2014]  0000000000000000 ffffffff817dbe2d ffffffff817dbe2d 0000000000000001
[Wed Apr 16 15:29:33 2014] Call Trace:
[Wed Apr 16 15:29:33 2014]  [<ffffffffa000d02c>] ? rcu_torture_init+0x2c/0x8b4 [rcutorture]
[Wed Apr 16 15:29:33 2014]  [<ffffffff81647951>] ? netlink_broadcast_filtered+0x121/0x3a0
[Wed Apr 16 15:29:33 2014]  [<ffffffff817dbe2d>] ? mutex_lock+0xd/0x2a
[Wed Apr 16 15:29:33 2014]  [<ffffffff817dbe2d>] ? mutex_lock+0xd/0x2a
[Wed Apr 16 15:29:33 2014]  [<ffffffff810e7022>] ? trace_module_notify+0x62/0x1d0
[Wed Apr 16 15:29:33 2014]  [<ffffffffa000d000>] ? 0xffffffffa000cfff
[Wed Apr 16 15:29:33 2014]  [<ffffffff8100034a>] do_one_initcall+0xfa/0x140
[Wed Apr 16 15:29:33 2014]  [<ffffffff8106b4ce>] ? __blocking_notifier_call_chain+0x5e/0x80
[Wed Apr 16 15:29:33 2014]  [<ffffffff810b3481>] load_module+0x1931/0x21b0
[Wed Apr 16 15:29:33 2014]  [<ffffffff810b0330>] ? show_initstate+0x50/0x50
[Wed Apr 16 15:29:33 2014]  [<ffffffff810b3d9e>] SyS_init_module+0x9e/0xc0
[Wed Apr 16 15:29:33 2014]  [<ffffffff817e4c22>] system_call_fastpath+0x16/0x1b
[Wed Apr 16 15:29:33 2014] Code:  Bad RIP value.
[Wed Apr 16 15:29:33 2014] RIP  [<ffffffffa0003000>] 0xffffffffa0003000
[Wed Apr 16 15:29:33 2014]  RSP <ffff8800db25dca0>
[Wed Apr 16 15:29:33 2014] CR2: ffffffffa0003000
[Wed Apr 16 15:29:33 2014] ---[ end trace 3e88c173037af84b ]---

This splat is due to the fact that torture_init_begin() and
torture_init_end() are both marked with __init, despite their use
at runtime.  This commit therefore removes __init from both functions.
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>