orangefs: fix typo in ornagefs_inode_lock

Orangefs fails to build on 32-bit SMP configurations due to a simple
misspelling, this does the obvious fix.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 575e9461 ("Orangefs: change pvfs2 filenames to orangefs")
Signed-off-by: Mike Marshall <hubcap@omnibond.com>