Revert "fs: ensure readFile[Sync] reads from the beginning"

This reverts commit 4444e73.

PR-URL: nodejs#10809
Reviewed-By: Anna Henningsen <anna@addaleax.net>

lib/fs.js

@@ -310,7 +310,7 @@ ReadFileContext.prototype.read = function() {
   req.oncomplete = readFileAfterRead;
   req.context = this;
 
-  binding.read(this.fd, buffer, offset, length, this.pos, req);
+  binding.read(this.fd, buffer, offset, length, -1, req);
 };
 
 ReadFileContext.prototype.close = function(err) {
@@ -447,11 +447,11 @@ function tryCreateBuffer(size, fd, isUserFd) {
   return buffer;
 }
 
-function tryReadSync(fd, isUserFd, buffer, pos, len, offset) {
+function tryReadSync(fd, isUserFd, buffer, pos, len) {
   var threw = true;
   var bytesRead;
   try {
-    bytesRead = fs.readSync(fd, buffer, pos, len, offset);
+    bytesRead = fs.readSync(fd, buffer, pos, len);
     threw = false;
   } finally {
     if (threw && !isUserFd) fs.closeSync(fd);
@@ -480,15 +480,15 @@ fs.readFileSync = function(path, options) {
 
   if (size !== 0) {
     do {
-      bytesRead = tryReadSync(fd, isUserFd, buffer, pos, size - pos, pos);
+      bytesRead = tryReadSync(fd, isUserFd, buffer, pos, size - pos);
       pos += bytesRead;
     } while (bytesRead !== 0 && pos < size);
   } else {
     do {
       // the kernel lies about many files.
       // Go ahead and try to read some bytes.
       buffer = Buffer.allocUnsafe(8192);
-      bytesRead = tryReadSync(fd, isUserFd, buffer, 0, 8192, pos);
+      bytesRead = tryReadSync(fd, isUserFd, buffer, 0, 8192);
       if (bytesRead !== 0) {
         buffers.push(buffer.slice(0, bytesRead));
       }