ALSA: alsa: riptide: don't use own hex_to_bin() method

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@nokia.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/riptide/riptide.c

@@ -97,6 +97,7 @@
 #include <linux/gameport.h>
 #include <linux/device.h>
 #include <linux/firmware.h>
+#include <linux/kernel.h>
 #include <asm/io.h>
 #include <sound/core.h>
 #include <sound/info.h>
@@ -667,13 +668,12 @@ static u32 atoh(const unsigned char *in, unsigned int len)
 	unsigned char c;
 
 	while (len) {
+		int value;
+
 		c = in[len - 1];
-		if ((c >= '0') && (c <= '9'))
-			sum += mult * (c - '0');
-		else if ((c >= 'A') && (c <= 'F'))
-			sum += mult * (c - ('A' - 10));
-		else if ((c >= 'a') && (c <= 'f'))
-			sum += mult * (c - ('a' - 10));
+		value = hex_to_bin(c);
+		if (value >= 0)
+			sum += mult * value;
 		mult *= 16;
 		--len;
 	}