ssb: Use scnprintf() for avoiding potential buffer overflow

Since snprintf() returns the would-be-output size instead of the
actual output size, the succeeding calls may go beyond the given
buffer limit.  Fix it by replacing with scnprintf().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/ssb/sprom.c

@@ -26,9 +26,9 @@ static int sprom2hex(const u16 *sprom, char *buf, size_t buf_len,
 	int i, pos = 0;
 
 	for (i = 0; i < sprom_size_words; i++)
-		pos += snprintf(buf + pos, buf_len - pos - 1,
+		pos += scnprintf(buf + pos, buf_len - pos - 1,
 				"%04X", swab16(sprom[i]) & 0xFFFF);
-	pos += snprintf(buf + pos, buf_len - pos - 1, "\n");
+	pos += scnprintf(buf + pos, buf_len - pos - 1, "\n");
 
 	return pos + 1;
 }