ufs: fix function declaration for ufs_truncate_blocks

sparse says:

    fs/ufs/inode.c:1195:6: warning: symbol 'ufs_truncate_blocks' was not declared. Should it be static?

Note that the forward declaration in the file is already marked static.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/ufs/inode.c

@@ -1191,7 +1191,7 @@ static int ufs_truncate(struct inode *inode, loff_t size)
 	return err;
 }
 
-void ufs_truncate_blocks(struct inode *inode)
+static void ufs_truncate_blocks(struct inode *inode)
 {
 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
 	      S_ISLNK(inode->i_mode)))