commit to add scp to the test sshd's path causes the t-envpass test to fail
when the test scp is given using a fully qualified path. Put this in a
helper function and only call it from the scp tests.
OpenBSD-Regress-ID: 7533dc1c4265c1de716abb062957994195b36df4
use cmp in a loop instead of diff -N to compare
directories. The former works on more platforms for Portable.
OpenBSD-Regress-ID: c3aa72807f9c488e8829a26ae50fe5bcc5b57099
dtucker@openbsd.org
djm@openbsd.org
millert@openbsd.org@openbsd.org