Revert "Use erlang:apply in hash_password to silence deprecation warning."

This reverts commit 776f2be396d9b73e81b8de3dc5b7c775d4fbf42f.

Change-Id: I5e2a798e3b1d16f5d2b637ccf2f3235b27bf3733
Reviewed-on: http://review.couchbase.org/35075
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>