Apply clang-tidy fixes for llvm-else-after-return in BuiltinDialectBytecode.cpp (NFC)

Author: joker-eph

mlir/lib/IR/BuiltinDialectBytecode.cpp

@@ -33,7 +33,8 @@ namespace {
 static unsigned getIntegerBitWidth(DialectBytecodeReader &reader, Type type) {
   if (auto intType = dyn_cast<IntegerType>(type)) {
     return intType.getWidth();
-  } else if (llvm::isa<IndexType>(type)) {
+  }
+  if (llvm::isa<IndexType>(type)) {
     return IndexType::kInternalStorageBitWidth;
   }
   reader.emitError()