LU-1940 ost: wait a while for OBD_FAIL_OST_EROFS

LU-1940 ost: wait a while for OBD_FAIL_OST_EROFS

for OSC, -EROFS is a recoverable error, it will resend the failed
request at most cl_resends times (obd->u.cli.cl_resends), and
its default value is 10, then for test case, the failed request
will be resent repeatly without delay, and the cl_resends could be
not enough to handle, replaces OBD_FAIL_CHECK with OBD_FAIL_TIMEOUT
will introduce some delay for -EROFS.

Signed-off-by: Hongchao Zhang <hongchao.zhang@whamcloud.com>
Change-Id: Ic2a8fe6f2d75e74f30d007940a8fd631997135e4
Reviewed-on: http://review.whamcloud.com/4622
Tested-by: Hudson
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Yu Jian <yujian@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>