ca_do_bch_correction() takes a random value from the stack and starts
counting bitflips from this value. Initialize the counter.
This passed unnoticed as the value is finally ignored in the call
hierarchy.
Fixes: 161df94b3c ("mtd: rawnand: cortina_nand: Add Cortina CAxxxx SoC support")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>