fs/udf: re-use hex_asc_upper_{hi,lo} macros

This patch cleans up udf_translate_to_linux() a bit by using globally defined
macros instead of custom code.

We can use sprintf(buf, "%04X", ...) there as well, but this one faster.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/unicode.c b/fs/udf/unicode.c
index 44b815e..afd470e 100644
--- a/fs/udf/unicode.c
+++ b/fs/udf/unicode.c
@@ -412,7 +412,6 @@
 	int extIndex = 0, newExtIndex = 0, hasExt = 0;
 	unsigned short valueCRC;
 	uint8_t curr;
-	const uint8_t hexChar[] = "0123456789ABCDEF";
 
 	if (udfName[0] == '.' &&
 	    (udfLen == 1 || (udfLen == 2 && udfName[1] == '.'))) {
@@ -477,10 +476,10 @@
 			newIndex = 250;
 		newName[newIndex++] = CRC_MARK;
 		valueCRC = crc_itu_t(0, fidName, fidNameLen);
-		newName[newIndex++] = hexChar[(valueCRC & 0xf000) >> 12];
-		newName[newIndex++] = hexChar[(valueCRC & 0x0f00) >> 8];
-		newName[newIndex++] = hexChar[(valueCRC & 0x00f0) >> 4];
-		newName[newIndex++] = hexChar[(valueCRC & 0x000f)];
+		newName[newIndex++] = hex_asc_upper_hi(valueCRC >> 8);
+		newName[newIndex++] = hex_asc_upper_lo(valueCRC >> 8);
+		newName[newIndex++] = hex_asc_upper_hi(valueCRC);
+		newName[newIndex++] = hex_asc_upper_lo(valueCRC);
 
 		if (hasExt) {
 			newName[newIndex++] = EXT_MARK;