ext4: Fix comparision of unsigned expression with < 0

In file ext4fs.c funtion ext4fs_read_file() compares an
unsigned expression with < 0 like below

	lbaint_t blknr;
	blknr = read_allocated_block(&(node->inode), i);
	if (blknr < 0)
		return -1;

blknr is of type ulong/uint64_t. read_allocated_block() returns
long int. So comparing blknr with < 0 will always be false. Instead
declare blknr as long int.

Similarly ext4/dev.c does a similar comparison. Drop the redundant
comparison.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

fs/ext4/dev.c

@@ -60,9 +60,8 @@ int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
 	}
 
 	/* Check partition boundaries */
-	if ((sector < 0) ||
-	    ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
-	     >= part_info->size)) {
+	if ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
+	    >= part_info->size) {
 		printf("%s read outside partition " LBAFU "\n", __func__,
 		       sector);
 		return 0;

fs/ext4/ext4fs.c

@@ -71,7 +71,7 @@ int ext4fs_read_file(struct ext2fs_node *node, loff_t pos,
 	blockcnt = lldiv(((len + pos) + blocksize - 1), blocksize);
 
 	for (i = lldiv(pos, blocksize); i < blockcnt; i++) {
-		lbaint_t blknr;
+		long int blknr;
 		int blockoff = pos - (blocksize * i);
 		int blockend = blocksize;
 		int skipfirst = 0;