case-insensitive mounts shouldn't use full_name_hash(). Make sure we
use the parent dentry's d_hash routine when one is set.
Reported-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>