cif: fix dead code

This issue was found by Coverity (CID 1202536)

This proposes a fix for a statement that creates dead code.
The "rc < 0" statement is within code that is run
with "rc > 0".

It seems like "err < 0" was meant to be used here.
This way, the error code is returned by the function.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Steve French <smfrench@gmail.com>