tal: optimize case where no (non-destructor) notifiers are used.
$ for i in `seq 10`; do ./samba-allocs talloc.dump --tal; done | stats.c --trim-outliers
Before:
Read 25998 nodes
Tal time:
2857988-
2981158(
2904324)ns
Tal_free time:
2417170-
2582088(
2470931)ns
Single tal_free time:
1551654-
1609583(
1575984)ns
After:
Read 25998 nodes
Tal time:
2780974-
2901323(
2839352)ns
Tal_free time:
2241725-
2355309(
2285165)ns
Single tal_free time:
1549908-
1612485(
1566609)ns
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>