vt: clean up the code - use kernel library

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/vt.c

@@ -105,6 +105,7 @@
 #include <asm/system.h>
 #include <linux/uaccess.h>
 #include <linux/kdb.h>
+#include <linux/ctype.h>
 
 #define MAX_NR_CON_DRIVER 16
 
@@ -1796,8 +1797,8 @@ static void do_con_trol(struct tty_struct *tty, struct vc_data *vc, int c)
 			vc->vc_state = ESnormal;
 		return;
 	case ESpalette:
-		if ( (c>='0'&&c<='9') || (c>='A'&&c<='F') || (c>='a'&&c<='f') ) {
-			vc->vc_par[vc->vc_npar++] = (c > '9' ? (c & 0xDF) - 'A' + 10 : c - '0');
+		if (isxdigit(c)) {
+			vc->vc_par[vc->vc_npar++] = hex_to_bin(c);
 			if (vc->vc_npar == 7) {
 				int i = vc->vc_par[0] * 3, j = 1;
 				vc->vc_palette[i] = 16 * vc->vc_par[j++];