mtd: introduce mtd_block_isbad interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/fs/logfs/dev_mtd.c b/fs/logfs/dev_mtd.c
index 0ca7a07..136c736 100644
--- a/fs/logfs/dev_mtd.c
+++ b/fs/logfs/dev_mtd.c
@@ -157,7 +157,7 @@
 		return NULL;
 
 	*ofs = 0;
-	while (mtd->block_isbad(mtd, *ofs)) {
+	while (mtd_block_isbad(mtd, *ofs)) {
 		*ofs += mtd->erasesize;
 		if (*ofs >= mtd->size)
 			return NULL;
@@ -177,7 +177,7 @@
 		return NULL;
 
 	*ofs = mtd->size - mtd->erasesize;
-	while (mtd->block_isbad(mtd, *ofs)) {
+	while (mtd_block_isbad(mtd, *ofs)) {
 		*ofs -= mtd->erasesize;
 		if (*ofs <= 0)
 			return NULL;