mtd: return badblockbits back

mtd: return badblockbits back

In commit 02b42482aaa34adfc4f5aae7e2f95d40b58cc1ec the initialization of
the backblockbits was accidentally removed. This patch returns it back,
because otherwise some NAND drivers are broken.

This problem was reported by "Saxena, Parth <parth.saxena@ti.com>" here:
http://lists.infradead.org/pipermail/linux-mtd/2011-April/035221.html

Reported-by: Saxena, Parth <parth.saxena@ti.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Tested-by: Saxena, Parth <parth.saxena@ti.com>
Acked-by: Saxena, Parth <parth.saxena@ti.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Cc: stable@kernel.org [2.6.36+]
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>