TTY: isdn, make some functions readable

Huh, this was a mess.

* Remove the 5 indent levels by just returning from isdn_tty_try_read
  when the conditions there are not satisfied.
* Use 'continue' in loop in isdn_tty_readmodem to save 2 levels.
* Chain 'if's in isdn_tty_modem_escape.
* Use 'continue' in loop in isdn_tty_carrier_timeout to save 1 level.

Better to look at this patch with -w -b.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/isdn/i4l/isdn_tty.c

@@ -65,9 +65,16 @@ isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
 	struct tty_struct *tty;
 	char last;
 
-	if (info->online) {
-		if ((tty = info->tty)) {
-			if (info->mcr & UART_MCR_RTS) {
+	if (!info->online)
+		return 0;
+
+	tty = info->tty;
+	if (!tty)
+		return 0;
+
+	if (!(info->mcr & UART_MCR_RTS))
+		return 0;
+
 	len = skb->len
 #ifdef CONFIG_ISDN_AUDIO
 		+ ISDN_AUDIO_SKB_DLECOUNT(skb)
@@ -75,7 +82,9 @@ isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
 		;
 
 	c = tty_buffer_request_room(tty, len);
-				if (c >= len) {
+	if (c < len)
+		return 0;
+
 #ifdef CONFIG_ISDN_AUDIO
 	if (ISDN_AUDIO_SKB_DLECOUNT(skb)) {
 		int l = skb->len;
@@ -102,12 +111,8 @@ isdn_tty_try_read(modem_info *info, struct sk_buff *skb)
 		tty_insert_flip_char(tty, last, TTY_NORMAL);
 	tty_flip_buffer_push(tty);
 	kfree_skb(skb);
+
 	return 1;
-				}
-			}
-		}
-	}
-	return 0;
 }
 
 /* isdn_tty_readmodem() is called periodically from within timer-interrupt.
@@ -125,16 +130,22 @@ isdn_tty_readmodem(void)
 	modem_info *info;
 
 	for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
-		if ((midx = dev->m_idx[i]) >= 0) {
+		midx = dev->m_idx[i];
+		if (midx < 0)
+			continue;
+
 		info = &dev->mdm.info[midx];
-			if (info->online) {
+		if (!info->online)
+			continue;
+
 		r = 0;
 #ifdef CONFIG_ISDN_AUDIO
 		isdn_audio_eval_dtmf(info);
 		if ((info->vonline & 1) && (info->emu.vpar[1]))
 			isdn_audio_eval_silence(info);
 #endif
-				if ((tty = info->tty)) {
+		tty = info->tty;
+		if (tty) {
 			if (info->mcr & UART_MCR_RTS) {
 				/* CISCO AsyncPPP Hack */
 				if (!(info->emu.mdmreg[REG_CPPP] & BIT_CPPP))
@@ -153,8 +164,6 @@ isdn_tty_readmodem(void)
 		} else
 			info->rcvsched = 1;
 	}
-		}
-	}
 	if (!resched)
 		isdn_timer_ctrl(ISDN_TIMER_MODEMREAD, 0);
 }
@@ -3769,13 +3778,13 @@ isdn_tty_modem_escape(void)
 	int midx;
 
 	for (i = 0; i < ISDN_MAX_CHANNELS; i++)
-		if (USG_MODEM(dev->usage[i]))
-			if ((midx = dev->m_idx[i]) >= 0) {
+		if (USG_MODEM(dev->usage[i]) && (midx = dev->m_idx[i]) >= 0) {
 			modem_info *info = &dev->mdm.info[midx];
 			if (info->online) {
 				ton = 1;
 				if ((info->emu.pluscount == 3) &&
-					    time_after(jiffies , info->emu.lastplus + PLUSWAIT2)) {
+				    time_after(jiffies,
+					    info->emu.lastplus + PLUSWAIT2)) {
 					info->emu.pluscount = 0;
 					info->online = 0;
 					isdn_tty_modem_result(RESULT_OK, info);
@@ -3839,15 +3848,14 @@ isdn_tty_carrier_timeout(void)
 
 	for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
 		modem_info *info = &dev->mdm.info[i];
-		if (info->dialing) {
+		if (!info->dialing)
+			continue;
 		if (info->emu.carrierwait++ > info->emu.mdmreg[REG_WAITC]) {
 			info->dialing = 0;
 			isdn_tty_modem_result(RESULT_NO_CARRIER, info);
 			isdn_tty_modem_hup(info, 1);
-			}
-			else
+		} else
 			ton = 1;
 	}
-	}
 	isdn_timer_ctrl(ISDN_TIMER_CARRIER, ton);
 }