Following up on r1453925, resolve a potentially uninitialized variable problem
caused by using the same name for an argument and a local variable. Apply
further query optimization by caching the properties in ram.

* subversion/libsvn_wc/wc_db.c
  (db_get_changed_props): New function.
  (db_read_inherited_props): Use db_get_changed_props to avoid querying the
    same NODES record again for every parent directory. Remove variable
    shadowing.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1453948 13f79535-47bb-0310-9956-ffa450edef68