service: separate statistics dump and reset

service: separate statistics dump and reset

No functional change intended.

service_dump_calls_per_lcore() was always called with a 0 reset flag.
service_dump_one() was called with either a 0 reset flag or a NULL
FILE pointer.

We can split the code for readability sake.

Note: there is no path to resetting calls_per_service[], this is left as
is.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>