Get verify_sdp.sh to find bogus script/symlink targets.
A customer had an issue due to /p4/1/bin/p4d_1 being a script
that calls /p4/common/bin/p4d, when it should have been calling
/p4/common/bin/p4d_1_bin. The verify_sdp.sh script should
check for this sort of thing.
In this specific case, /p4/1/bin/p4d_1 can be a script (if
case-insensitive) or a symlink (for a case-sensitive instance).
In either case, we want to make sure the symlink target is
correct.