The fasttrap ioctl used to create probes takes a variable-sized argument.
It was not being correctly copied into the kernel on FreeBSD, and as a
result, probes with multiple probe sites were not being created properly.
To fix this, change the ioctl definition so that the fasttrap ioctl handler
is responsible for copying in userland data.

Submitted by:	Prashanth Kumar <pra_udupi@yahoo.co.in>
MFC after:	1 month