[MTD] NAND: Allow operation without bad block table

Small bugfix. Sometimes it may be handy not to have bbt.
So, this->bbt might be NULL.

Signed-off-by: Artem B. Bityuckiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1 file changed