mtd: rawnand: cortina_nand: missing initialization

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: 161df94b3c43 ("mtd: rawnand: cortina_nand: Add Cortina CAxxxx SoC support")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/drivers/mtd/nand/raw/cortina_nand.c b/drivers/mtd/nand/raw/cortina_nand.c
index 12bd1de..81fa878 100644
--- a/drivers/mtd/nand/raw/cortina_nand.c
+++ b/drivers/mtd/nand/raw/cortina_nand.c
@@ -546,7 +546,7 @@
 	struct nand_drv *info =
 	    (struct nand_drv *)nand_get_controller_data(chip);
 	unsigned int reg_v, err_loc0, err_loc1;
-	int k, max_bitflips;
+	int k, max_bitflips = 0;
 
 	for (k = 0; k < (err_num + 1) / 2; k++) {
 		reg_v = readl(&info->reg->flash_nf_bch_error_loc01 + k);