Replace the completely arbitrary '3' with '9' for the number of frames to
skip using the DTrace 'profile' provider on ARM. This causes stack traces
to skip various driver-and callout-related things as they do on x86, where
the likewise arbitrary values are '6' (32-bit) and '10' (64-bit) for
similar sorts of reasons.

MFC after: 3 days
Sponsored by: DARPA, AFRL