drivers: isdn: use kernel macros to convert hex digit

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/capi/capidrv.c

@@ -1450,12 +1450,9 @@ static void handle_dtrace_data(capidrv_contr *card,
     	}
 
 	for (p = data, end = data+len; p < end; p++) {
-		u8 w;
 		PUTBYTE_TO_STATUS(card, ' ');
-		w = (*p >> 4) & 0xf;
-		PUTBYTE_TO_STATUS(card, (w < 10) ? '0'+w : 'A'-10+w);
-		w = *p & 0xf;
-		PUTBYTE_TO_STATUS(card, (w < 10) ? '0'+w : 'A'-10+w);
+		PUTBYTE_TO_STATUS(card, hex_asc_hi(*p));
+		PUTBYTE_TO_STATUS(card, hex_asc_lo(*p));
 	}
 	PUTBYTE_TO_STATUS(card, '\n');
 

drivers/isdn/hisax/q931.c

@@ -1152,20 +1152,11 @@ QuickHex(char *txt, u_char * p, int cnt)
 {
 	register int i;
 	register char *t = txt;
-	register u_char w;
 
 	for (i = 0; i < cnt; i++) {
 		*t++ = ' ';
-		w = (p[i] >> 4) & 0x0f;
-		if (w < 10)
-			*t++ = '0' + w;
-		else
-			*t++ = 'A' - 10 + w;
-		w = p[i] & 0x0f;
-		if (w < 10)
-			*t++ = '0' + w;
-		else
-			*t++ = 'A' - 10 + w;
+		*t++ = hex_asc_hi(p[i]);
+		*t++ = hex_asc_lo(p[i]);
 	}
 	*t++ = 0;
 	return (t - txt);