fs: two minor optimizations

* tryStatSync should not return any value
  If the function threw, it would never reach that code path.

* only use try catch if necessary
  lchmodSync does not need the second try catch in most cases.

PR-URL: #14055
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>

lib/fs.js

@@ -521,7 +521,6 @@ function tryStatSync(fd, isUserFd) {
   } finally {
     if (threw && !isUserFd) fs.closeSync(fd);
   }
-  return !threw;
 }
 
 function tryCreateBuffer(size, fd, isUserFd) {
@@ -553,10 +552,11 @@ fs.readFileSync = function(path, options) {
   var isUserFd = isFd(path); // file descriptor ownership
   var fd = isUserFd ? path : fs.openSync(path, options.flag || 'r', 0o666);
 
+  tryStatSync(fd, isUserFd);
   // Use stats array directly to avoid creating an fs.Stats instance just for
   // our internal use.
   var size;
-  if (tryStatSync(fd, isUserFd) && (statValues[1/*mode*/] & S_IFMT) === S_IFREG)
+  if ((statValues[1/*mode*/] & S_IFMT) === S_IFREG)
     size = statValues[8/*size*/];
   else
     size = 0;
@@ -1085,7 +1085,7 @@ if (constants.O_SYMLINK !== undefined) {
         callback(err);
         return;
       }
-      // prefer to return the chmod error, if one occurs,
+      // Prefer to return the chmod error, if one occurs,
       // but still try to close, and report closing errors if they occur.
       fs.fchmod(fd, mode, function(err) {
         fs.close(fd, function(err2) {
@@ -1098,20 +1098,18 @@ if (constants.O_SYMLINK !== undefined) {
   fs.lchmodSync = function(path, mode) {
     var fd = fs.openSync(path, constants.O_WRONLY | constants.O_SYMLINK);
 
-    // prefer to return the chmod error, if one occurs,
+    // Prefer to return the chmod error, if one occurs,
     // but still try to close, and report closing errors if they occur.
-    var err, err2, ret;
+    var ret;
     try {
       ret = fs.fchmodSync(fd, mode);
-    } catch (er) {
-      err = er;
-    }
-    try {
-      fs.closeSync(fd);
-    } catch (er) {
-      err2 = er;
+    } catch (err) {
+      try {
+        fs.closeSync(fd);
+      } catch (ignore) {}
+      throw err;
     }
-    if (err || err2) throw (err || err2);
+    fs.closeSync(fd);
     return ret;
   };
 }