minor #16238 [Form] Remove unneeded catch and re-throw in DateTimeToStringTransformer (MisatoTremor)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes #16238).

Discussion
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[Form] Remove unneeded catch and re-throw in DateTimeToStringTransformer

| Q             | A
| ------------- | ---
| Fixed tickets | #16237
| License       | MIT

Also fixed PHPDoc param for ``transform``.

Commits
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2c9b283 [Form] Simplify DateTimeToStringTransformer Avoid unneeded catch and re-throw of the same exception.

src/Symfony/Component/Form/Extension/Core/DataTransformer/DateTimeToStringTransformer.php

@@ -90,7 +90,7 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
      * Transforms a DateTime object into a date string with the configured format
      * and timezone.
      *
-     * @param \DateTime|\DateTimeInterface $dateTime A DateTime object
+     * @param \DateTime|\DateTimeInterface $value A DateTime object
      *
      * @return string A value as produced by PHP's date() function
      *
@@ -142,7 +142,6 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
             throw new TransformationFailedException('Expected a string.');
         }
 
-        try {
         $outputTz = new \DateTimeZone($this->outputTimezone);
         $dateTime = \DateTime::createFromFormat($this->parseFormat, $value, $outputTz);
 
@@ -157,6 +156,7 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
             );
         }
 
+        try {
             // On PHP versions < 5.3.7 we need to emulate the pipe operator
             // and reset parts not given in the format to their equivalent
             // of the UNIX base timestamp.
@@ -224,8 +224,6 @@ class DateTimeToStringTransformer extends BaseDateTimeTransformer
             if ($this->inputTimezone !== $this->outputTimezone) {
                 $dateTime->setTimezone(new \DateTimeZone($this->inputTimezone));
             }
-        } catch (TransformationFailedException $e) {
-            throw $e;
         } catch (\Exception $e) {
             throw new TransformationFailedException($e->getMessage(), $e->getCode(), $e);
         }