seq_buf_putc
extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
seq_buf_putc(s, c);
seq_buf_putc(&s, '\n');
seq_buf_putc(s, '\n');
seq_buf_putc(s, '\n');
seq_buf_putc(&s->seq, c);
seq_buf_putc(out, ' ');
seq_buf_putc(out, '\n');
EXPORT_SYMBOL_GPL(seq_buf_putc);
seq_buf_putc(&s, 'd');
seq_buf_putc(&s, 'e');
seq_buf_putc(&s, 'a');
seq_buf_putc(&s, 'b');
seq_buf_putc(&s, 'c');