[POWERPC] hvcbeat: Fix buffer manipulation

This fixes a potential bug at drivers/char/hvc_beat.c.
 - hvc_put_term_char routine will decrement "rest" variable twice,
   and forget to advance "buf" pointer by "nlen" bytes.
This bug was not hit previously because the output handler in
drivers/char/hvc_console.c splits given output into 16 bytes
at maximum.

Reported-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

drivers/char/hvc_beat.c

@@ -78,8 +78,8 @@ static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt)
 	for (rest = cnt; rest > 0; rest -= nlen) {
 		nlen = (rest > 16) ? 16 : rest;
 		memcpy(kb, buf, nlen);
-		beat_put_term_char(vtermno, rest, kb[0], kb[1]);
-		rest -= nlen;
+		beat_put_term_char(vtermno, nlen, kb[0], kb[1]);
+		buf += nlen;
 	}
 	return cnt;
 }