mtd: pxa3xx_nand: NULL dereference in pxa3xx_nand_probe

commit 52d039fdaa78c5a9f9bc2940ad58d7ed76b8336d upstream.

"info->cmdset" gets dereferenced in __readid() so it needs to be
initialized earlier in the function.  This bug was introduced in
18c81b1828f8 "mtd: pxa3xx_nand: remove the flash info in driver
structure".

Reported-and-tested-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>