g2d: fix BUG() when logging events

g2d: fix BUG() when logging events

The following message caused by smp_processor_id() when it is not
called in atomic context to keep the consistency of the processor
id during the task related to the processor id is completed.

<3>[   66.158972]  [7:composer@2.1-se: 1919] BUG: using smp_processor_id() in preemptible [00000000] code: composer@2.1-se/1919
<4>[   66.158989]  [7:composer@2.1-se: 1919] caller is debug_smp_processor_id+0x1c/0x24
<4>[   66.158999]  [7:composer@2.1-se: 1919] CPU: 7 PID: 1919 Comm: composer@2.1-se Tainted: G S              4.14.13-g7ad8263aec9d #83
<4>[   66.159006]  [7:composer@2.1-se: 1919] Hardware name: Samsung UNIVERSAL9810 board based on EXYNOS9810 (DT)
<4>[   66.159012]  [7:composer@2.1-se: 1919] Call trace:
<4>[   66.159024]  [7:composer@2.1-se: 1919] [<ffffff800808b4f4>] dump_backtrace+0x0/0x418
<4>[   66.159032]  [7:composer@2.1-se: 1919] [<ffffff800808b920>] show_stack+0x14/0x1c
<4>[   66.159042]  [7:composer@2.1-se: 1919] [<ffffff80087a442c>] dump_stack+0x88/0xac
<4>[   66.159049]  [7:composer@2.1-se: 1919] [<ffffff800837cca4>] check_preemption_disabled+0xd0/0xf4
<4>[   66.159055]  [7:composer@2.1-se: 1919] [<ffffff800837cce4>] debug_smp_processor_id+0x1c/0x24
<4>[   66.159065]  [7:composer@2.1-se: 1919] [<ffffff80084324c0>] g2d_stamp_task+0xa0/0x104
<4>[   66.159071]  [7:composer@2.1-se: 1919] [<ffffff800842ac90>] g2d_ioctl+0x374/0x424
<4>[   66.159080]  [7:composer@2.1-se: 1919] [<ffffff8008203a64>] vfs_ioctl+0x20/0x38
<4>[   66.159086]  [7:composer@2.1-se: 1919] [<ffffff8008204548>] do_vfs_ioctl+0x9c0/0xa6c
<4>[   66.159093]  [7:composer@2.1-se: 1919] [<ffffff8008204654>] SyS_ioctl+0x60/0x88

Even though g2d driver does not need the consistency because it just
uses it for logging the current CPU, it is required to kill the
unnecessary messages.

Change-Id: Ie6be45bc1457cb8936c388f80bc9b837fb4d2afa
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>