kernel: mtdsplit: document Seama splitter a bit

Rename kernel_size variable as it includes whole entity size, not just a
kernel size. Also update comments to match it and describe better what
are we checking/looking for.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 48480

target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_seama.c

@@ -33,7 +33,7 @@ static int mtdsplit_parse_seama(struct mtd_info *master,
 				struct mtd_part_parser_data *data)
 {
 	struct seama_header hdr;
-	size_t hdr_len, retlen, kernel_size;
+	size_t hdr_len, retlen, kernel_ent_size;
 	size_t rootfs_offset;
 	struct mtd_partition *parts;
 	int err;
@@ -50,18 +50,20 @@ static int mtdsplit_parse_seama(struct mtd_info *master,
 	if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC)
 		return -EINVAL;
 
-	kernel_size = hdr_len + be32_to_cpu(hdr.size) +
-		      be16_to_cpu(hdr.metasize);
-	if (kernel_size > master->size)
+	kernel_ent_size = hdr_len + be32_to_cpu(hdr.size) +
+			  be16_to_cpu(hdr.metasize);
+	if (kernel_ent_size > master->size)
 		return -EINVAL;
 
-	/* Find the rootfs after the kernel. */
-	err = mtd_check_rootfs_magic(master, kernel_size);
+	/* Check for the rootfs right after Seama entity with a kernel. */
+	err = mtd_check_rootfs_magic(master, kernel_ent_size);
 	if (!err) {
-		rootfs_offset = kernel_size;
+		rootfs_offset = kernel_ent_size;
 	} else {
 		/*
-		 * The size in the header might cover the rootfs as well.
+		 * On some devices firmware entity might contain both: kernel
+		 * and rootfs. We can't determine kernel size so we just have to
+		 * look for rootfs magic.
 		 * Start the search from an arbitrary offset.
 		 */
 		err = mtd_find_rootfs_from(master, SEAMA_MIN_ROOTFS_OFFS,