perf/x86/intel: Fix build warning in intel_pmu_drain_pebs_nhm()

perf/x86/intel: Fix build warning in intel_pmu_drain_pebs_nhm()

Fengguang Wu reported this build warning:

    arch/x86/kernel/cpu/perf_event_intel_ds.c: In function 'intel_pmu_drain_pebs_nhm':
    arch/x86/kernel/cpu/perf_event_intel_ds.c:964:2: warning: format '%ld' expects argument of type 'long int', but argument 4 has type 'int'

Because pointer arithmetics result type is bitness dependent there's no natural
type to use here, cast it to long.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-jbpauwxJqtf24luewcsdFith@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>