[MTD] [NAND] S3C2410: Uninitialised variable cleanup

~ Avoid warning without generating code.
  (I don't even get the warning without the macro uninitialized_var).

Signed-off-by: Nelson Castillo <arhuaco@freaks-unidos.net>
[ben-linux@fluff.org: subject cleanup]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>