mtd: do use mtd->point directly

Remove direct usage of the "mtd->point" function pointer. Instead,
test the mtd_point() return code for '-EOPNOTSUPP'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

fs/jffs2/erase.c

@@ -336,12 +336,11 @@ static int jffs2_block_check_erase(struct jffs2_sb_info *c, struct jffs2_erasebl
 	uint32_t ofs;
 	size_t retlen;
 	int ret = -EIO;
-
-	if (c->mtd->point) {
 	unsigned long *wordebuf;
 
 	ret = mtd_point(c->mtd, jeb->offset, c->sector_size, &retlen,
 			&ebuf, NULL);
+	if (ret != -EOPNOTSUPP) {
 		if (ret) {
 			D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
 			goto do_flash_read;

fs/jffs2/readinode.c

@@ -62,17 +62,15 @@ static int check_node_data(struct jffs2_sb_info *c, struct jffs2_tmp_dnode_info
 #ifndef __ECOS
 	/* TODO: instead, incapsulate point() stuff to jffs2_flash_read(),
 	 * adding and jffs2_flash_read_end() interface. */
-	if (c->mtd->point) {
-		err = mtd_point(c->mtd, ofs, len, &retlen, (void **)&buffer,
-				NULL);
+	err = mtd_point(c->mtd, ofs, len, &retlen, (void **)&buffer, NULL);
 	if (!err && retlen < len) {
 		JFFS2_WARNING("MTD point returned len too short: %zu instead of %u.\n", retlen, tn->csize);
 		mtd_unpoint(c->mtd, ofs, retlen);
-		} else if (err)
+	} else if (err) {
+		if (err != -EOPNOTSUPP)
 			JFFS2_WARNING("MTD point failed: error code %d.\n", err);
-		else
+	} else
 		pointed = 1; /* succefully pointed to device */
-	}
 #endif
 
 	if (!pointed) {

fs/jffs2/scan.c

@@ -105,7 +105,7 @@ int jffs2_scan_medium(struct jffs2_sb_info *c)
 			mtd_unpoint(c->mtd, 0, pointlen);
 			flashbuf = NULL;
 		}
-		if (ret)
+		if (ret && ret != -EOPNOTSUPP)
 			D1(printk(KERN_DEBUG "MTD point failed %d\n", ret));
 	}
 #endif

include/linux/mtd/mtd.h

@@ -259,6 +259,8 @@ static inline int mtd_point(struct mtd_info *mtd, loff_t from, size_t len,
 			    size_t *retlen, void **virt, resource_size_t *phys)
 {
 	*retlen = 0;
+	if (!mtd->point)
+		return -EOPNOTSUPP;
 	return mtd->point(mtd, from, len, retlen, virt, phys);
 }