perf sched: Use RC_CHK_EQUAL() to compare pointers

So that it can check two pointers to the same object properly when
REFCNT_CHECKING is on.

Fixes: 78c32f4c ("libperf rc_check: Add RC_CHK_EQUAL")
Reviewed-by: Ian Rogers <irogers@google.com>
Tested-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250703014942.1369397-7-namhyung@kernel.org


Signed-off-by: Namhyung Kim <namhyung@kernel.org>