exfat: Simplify exfat_utf8_d_hash() for code points above U+FFFF

Function partial_name_hash() takes long type value into which can be stored
one Unicode code point. Therefore conversion from UTF-32 to UTF-16 is not
needed.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>

fs/exfat/namei.c

@@ -147,16 +147,10 @@ static int exfat_utf8_d_hash(const struct dentry *dentry, struct qstr *qstr)
 			return charlen;
 
 		/*
-		 * Convert to UTF-16: code points above U+FFFF are encoded as
-		 * surrogate pairs.
 		 * exfat_toupper() works only for code points up to the U+FFFF.
 		 */
-		if (u > 0xFFFF) {
-			hash = partial_name_hash(exfat_high_surrogate(u), hash);
-			hash = partial_name_hash(exfat_low_surrogate(u), hash);
-		} else {
-			hash = partial_name_hash(exfat_toupper(sb, u), hash);
-		}
+		hash = partial_name_hash(u <= 0xFFFF ? exfat_toupper(sb, u) : u,
+					 hash);
 	}
 
 	qstr->hash = end_name_hash(hash);