buffer: remove unreachable code

PR-URL: #38537
Reviewed-By: Rich Trott <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: pd4d10

lib/buffer.js

@@ -252,10 +252,7 @@ function _copyActual(source, target, targetStart, sourceStart, sourceEnd) {
     sourceEnd = sourceStart + target.length - targetStart;
 
   let nb = sourceEnd - sourceStart;
-  const targetLen = target.length - targetStart;
   const sourceLen = source.length - sourceStart;
-  if (nb > targetLen)
-    nb = targetLen;
   if (nb > sourceLen)
     nb = sourceLen;