NFS: Use seq_putc() in nfs_show_stats()

A single character (line break) should be put into a sequence.
Thus use the corresponding function “seq_putc”.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

fs/nfs/super.c

@@ -905,7 +905,7 @@ int nfs_show_stats(struct seq_file *m, struct dentry *root)
 			seq_printf(m, "%Lu ", totals.fscache[i]);
 	}
 #endif
-	seq_printf(m, "\n");
+	seq_putc(m, '\n');
 
 	rpc_clnt_show_stats(m, nfss->client);