MFC r300938, r342154

r300938 by ngie:
Remove the sa(8) tests if MK_ACCT == no when "make delete-old" is run

sa(8) is conditionally installed based on MK_ACCT != no today

Sponsored by: EMC / Isilon Storage Division

r342154:
OptionalObsoleteFiles: Fix deleting usr/tests/usr.sbin/sa

It's a directory, not a file.

Reported by: ngie
X-MFC-With: 300938