udf: Fix some sign-conversion warnings

Fix some warnings that appear when compiling with -Wconversion.
A sub-optimal choice of variable type leads to warnings about
conversion in both directions between unsigned and signed.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 7d2a95c..c23744d 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -480,7 +480,7 @@ static int udf_do_extend_file(struct inode *inode,
 	int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
 	struct super_block *sb = inode->i_sb;
 	struct kernel_lb_addr prealloc_loc = {};
-	int prealloc_len = 0;
+	uint32_t prealloc_len = 0;
 	struct udf_inode_info *iinfo;
 	int err;
 
@@ -1193,7 +1193,7 @@ int udf_setsize(struct inode *inode, loff_t newsize)
 {
 	int err;
 	struct udf_inode_info *iinfo;
-	int bsize = i_blocksize(inode);
+	unsigned int bsize = i_blocksize(inode);
 
 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 	      S_ISLNK(inode->i_mode)))