Update variable assignment for callable check

Refactor variable assignment for callable type check.

Author: staabm

src/Type/Php/ArrayMapFunctionReturnTypeExtension.php

@@ -41,12 +41,12 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 		if ($numArgs < 2) {
 			return null;
 		}
-		$x=1;
 
 		$singleArrayArgument = !isset($functionCall->getArgs()[2]);
 		$callback = $functionCall->getArgs()[0]->value;
 		$callableType = $scope->getType($callback);
 		$callableIsNull = $callableType->isNull()->yes();
+		$x=$callableType->isNull()->yes();
 
 		if ($callableType->isCallable()->yes()) {
 			$valueType = $scope->getType(new FuncCall(