Fix out of range commit checking in cache_inode_commit

Code returned the wrong error code, and didn't set *status. Apparently before
a number of logging buffer changes, the uninitialized memory was initialized
to something that resulted in the right error so pynfs CMT4 passed. After a
bunch of changes, it became initialized to zero resulting in a success return.

Signed-off-by: Frank Filz <ffilz@us.ibm.com>