scripts/tags.sh: add regex to map kprobe helpers

Add regex for [get|free]_[insn|optinsn|dmainsn]_slot() functions.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michal Marek <mmarek@suse.com>