nilfs2: avoid bare use of 'unsigned'

This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
bare use of 'unsigned'".

Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jp
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index 8fc73d0..57ec6af 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -685,7 +685,8 @@
 }
 
 static int nilfs_btree_lookup_contig(const struct nilfs_bmap *btree,
-				     __u64 key, __u64 *ptrp, unsigned maxblocks)
+				     __u64 key, __u64 *ptrp,
+				     unsigned int maxblocks)
 {
 	struct nilfs_btree_path *path;
 	struct nilfs_btree_node *node;