Allow hex literals to pass w/ groups of 2

Author: cgm616

clippy_lints/src/literal_representation.rs

@@ -368,7 +368,7 @@ impl LiteralDigitGrouping {
 
         let first = groups.next().expect("At least one group");
 
-        if (radix == Radix::Binary || radix == Radix::Hexadecimal) && groups.any(|i| i % 4 != 0) {
+        if (radix == Radix::Binary || radix == Radix::Hexadecimal) && groups.any(|i| i != 4 || i != 2) {
             return Err(WarningType::UnusualByteGrouping);
         }