drivers/perf: arm_pmu_acpi: Release memory obtained by kasprintf

Free memory region, if arm_pmu_acpi_probe is not successful.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>