nanddump: change default to --bb=skipbad

since mtd-utils 1.4.7, the default behaviour of nanddump is skipbad
(commit 2521d4f1b6b9866a9c89f3c11a4f6a3d763ff1d7)

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed