udf: Fix signed/unsigned format specifiers

Fix problems noted in compilion with -Wformat=2 -Wformat-signedness.
In particular, a mismatch between the signedness of a value and the
signedness of its format specifier can result in unsigned values being
printed as negative numbers, e.g.:

  Partition (0 type 1511) starts at physical 460, block length -1779968542

...which occurs when mounting a large (> 1 TiB) UDF partition.

Changes since V1:
* Fixed additional issues noted in udf_bitmap_free_blocks(),
  udf_get_fileident(), udf_show_options()

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index d3f18a6..0458dd4 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -840,7 +840,7 @@ static int udf_rmdir(struct inode *dir, struct dentry *dentry)
 	if (retval)
 		goto end_rmdir;
 	if (inode->i_nlink != 2)
-		udf_warn(inode->i_sb, "empty directory has nlink != 2 (%d)\n",
+		udf_warn(inode->i_sb, "empty directory has nlink != 2 (%u)\n",
 			 inode->i_nlink);
 	clear_nlink(inode);
 	inode->i_size = 0;
@@ -882,7 +882,7 @@ static int udf_unlink(struct inode *dir, struct dentry *dentry)
 		goto end_unlink;
 
 	if (!inode->i_nlink) {
-		udf_debug("Deleting nonexistent file (%lu), %d\n",
+		udf_debug("Deleting nonexistent file (%lu), %u\n",
 			  inode->i_ino, inode->i_nlink);
 		set_nlink(inode, 1);
 	}