mtd: onenand: make onenand_scan_bbt() static

Like was done in commit 17799359e7
("mtd: nand_bbt: make nand_scan_bbt() static") for the NAND code, this
commit makes the onenand_scan_bbt() function static in the OneNAND
code, since it is only used in onenand_bbt.c itself.

Consequently, the EXPORT_SYMBOL() and declaration in bbm.h are also
removed.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/onenand/onenand_bbt.c

@@ -179,7 +179,7 @@ static int onenand_isbad_bbt(struct mtd_info *mtd, loff_t offs, int allowbbt)
  * by the onenand_release function.
  *
  */
-int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
+static int onenand_scan_bbt(struct mtd_info *mtd, struct nand_bbt_descr *bd)
 {
 	struct onenand_chip *this = mtd->priv;
 	struct bbm_info *bbm = this->bbm;
@@ -248,5 +248,4 @@ int onenand_default_bbt(struct mtd_info *mtd)
 	return onenand_scan_bbt(mtd, bbm->badblock_pattern);
 }
 
-EXPORT_SYMBOL(onenand_scan_bbt);
 EXPORT_SYMBOL(onenand_default_bbt);