Generic/DisallowLongArraySyntax: simplify if statement

This commit uses a single isset() to check if two variables are set
instead of using two isset() calls.

Author: rodrigoprimo

src/Standards/Generic/Sniffs/Arrays/DisallowLongArraySyntaxSniff.php

@@ -45,9 +45,7 @@ public function process(File $phpcsFile, $stackPtr)
 
         $error = 'Short array syntax must be used to define arrays';
 
-        if (isset($tokens[$stackPtr]['parenthesis_opener']) === false
-            || isset($tokens[$stackPtr]['parenthesis_closer']) === false
-        ) {
+        if (isset($tokens[$stackPtr]['parenthesis_opener'], $tokens[$stackPtr]['parenthesis_closer']) === false) {
             // Live coding/parse error, just show the error, don't try and fix it.
             $phpcsFile->addError($error, $stackPtr, 'Found');
             return;