oprofile: fix an overflow in ppro code

reset_value was changed from long to u64 in commit
b9917028

 (oprofile: Implement Intel
architectural perfmon support)

But dynamic allocation of this array use a wrong type (long instead of
u64)

Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>