sched-attr: Fix a bug when CPU_BOOSTING_RESET_ON_FORK is set

sched-attr: Fix a bug when CPU_BOOSTING_RESET_ON_FORK is set

Fix the bug that occurs when the SYS_sched_setattr system call is invoked
while CPU_BOOSTING_FORCE_RESET_ON_FLAG is enabled.
This is because SYS_sched_setattr is different from sched_setscheduler().
sched_setscheduler receives flag argument through policy argument.
On the other hand, policy and flags are separated in SYS_sched_setattr.

sched_setscheduler with CPU_BOOSTING_RESET_ON_FORK:
policy = POLICY | SCHED_RESET_ON_FORK (ORed in policy)

SYS_sched_setattr with CPU_BOOSTING_RESET_ON_FORK:
policy = POLICY
flags |= 0x01 (0x01 is SCHED_FLAG_RESET_ON_FORK)

Change-Id: I96356357e6399c2377244b0f95fe36406a936f3d
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>