Reiserfs's readpage does not notice i/o errors.  This patch makes
reiserfs_readpage to return -EIO when i/o error appears.

This patch makes reiserfs to not ignore I/O error on readpage.
Signed-off-by: NQu Fuping <fs@ercist.iscas.ac.cn>
Signed-off-by: NVladimir V. Saveliev <vs@namesys.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>