uclampset: fix lost-update race in set_uclamp_one()

uclampset: fix lost-update race in set_uclamp_one()

The function unconditionally sets both SCHED_FLAG_UTIL_CLAMP_MIN and
SCHED_FLAG_UTIL_CLAMP_MAX in sa.sched_flags regardless of which values
the user actually requested to change.

This creates a lost-update race: sched_getattr() fetches the current
clamp values, but between that call and sched_setattr(), another thread
may legitimately update the value we did not intend to touch. Because
both flags are always set, sched_setattr() forces the kernel to apply
the stale cached value, silently overwriting the concurrent update.

Fix by setting the flags conditionally.

Signed-off-by: Furkan Caliskan <frn1furkan10@gmail.com>