databases/rocksdb: Try to find the reason why it is broken on our package building clusters

• Locate all shared libraries before running strip
• Clean up Makefile:
  • Use INSTALL_LIB to install librocksdb_tools.so
  • Remove PKGNAMESUFFIX: it is no-op after decouple rocksdb-lite from rocksdb (09bd0656bb445fed1675360acc33460e6d6fde44 and e4bc1f63b9dbdbde2463e8e4e33687aceb51bf1e)

from poudriere log [1]:
...

CCLD     librocksdb.so.7.3.1

ln -fs librocksdb.so.7.3.1 librocksdb.so.7.3
ln -fs librocksdb.so.7.3.1 librocksdb.so.7
ln -fs librocksdb.so.7.3.1 librocksdb.so
...
[ -e librocksdb.so.7.3.1 ] && gmake install-shared || :
...
/usr/bin/strip /wrkdirs/usr/ports/databases/rocksdb/work/stage/usr/local/lib/librocksdb.so /wrkdirs/usr/ports/databases/rocksdb/work/stage/usr/local/lib/librocksdb_tools.so
strip: open /wrkdirs/usr/ports/databases/rocksdb/work/stage/usr/local/lib/librocksdb.so failed: No such file or directory

• Error code 1

Stop.
make: stopped in /usr/ports/databases/rocksdb

Reference: http://beefy2.nyi.freebsd.org/data/123amd64-quarterly/3dc475798ba8/logs/rocksdb-7.3.1.log [1]