orangefs: Add octal zero prefix

This patch adds a missing zero to mode 755 specification required to
express it in octal numeral system.

Reported-by: Łukasz Wrochna <l.wrochna@samsung.com>
Signed-off-by: Artur Świgoń <a.swigon@partner.samsung.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>