Simplify hexchar

test.c

@@ -39,7 +39,7 @@
 char hexchar(uint8_t x)
 {
     if (x < 10) return x + '0';
-    if (10 <= x && x < 16) return x - 10 + 'A';
+    if (x < 16) return x - 10 + 'A';
     UNREACHABLE("hexchar");
 }