arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init()

arm_pmu: Drop redundant armpmu->map_event() in armpmu_event_init()

__hw_perf_event_init() already calls armpmu->map_event() callback, and also
returns its error code including -ENOENT, along with a debug callout. Hence
an additional armpmu->map_event() check for -ENOENT is redundant.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20221202015611.338499-1-anshuman.khandual@arm.com
Signed-off-by: Will Deacon <will@kernel.org>