Fix inconsistent return points.

Author: derrabus

Data/Generator/TimezoneDataGenerator.php

@@ -84,13 +84,13 @@ protected function generateDataForLocale(BundleEntryReaderInterface $reader, $te
         // Don't generate aliases, as they are resolved during runtime
         // Unless an alias is needed as fallback for de-duplication purposes
         if (isset($this->localeAliases[$displayLocale]) && !$this->generatingFallback) {
-            return;
+            return null;
         }
 
         $localeBundle = $reader->read($tempDir, $displayLocale);
 
         if (!isset($localeBundle['zoneStrings']) || null === $localeBundle['zoneStrings']) {
-            return;
+            return null;
         }
 
         $data = [
@@ -115,7 +115,7 @@ protected function generateDataForLocale(BundleEntryReaderInterface $reader, $te
             $data['Meta'] = array_diff($data['Meta'], $fallback['Meta']);
         }
         if (!$data['Names'] && !$data['Meta']) {
-            return;
+            return null;
         }
 
         $this->zoneIds = array_merge($this->zoneIds, array_keys($data['Names']));

Locale.php

@@ -104,11 +104,7 @@ public static function getFallback($locale): ?string
 
         // Don't return default fallback for "root", "meta" or others
         // Normal locales have two or three letters
-        if (\strlen($locale) < 4) {
-            return self::$defaultFallback;
-        }
-
-        return null;
+        return \strlen($locale) < 4 ? self::$defaultFallback : null;
     }
 
     /**