minor symfony#10777 Fix variable name in code snippet (freiondrej)

This PR was submitted for the 4.2 branch but it was merged into the 3.4 branch instead (closes symfony#10777).

Discussion
----------

Fix variable name in code snippet

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/roadmap for the list of maintained branches).

If your pull request documents a NEW FEATURE, use the same Symfony branch where
the feature was introduced (and `master` for features of unreleased versions).

-->

Commits
-------

f21f37d Fix variable name in code snippet

Author: javiereguiluz

components/asset.rst

@@ -215,7 +215,7 @@ that path over and over again::
     // result: /static/images/logo.png?v1
 
     // Base path is ignored when using absolute paths
-    echo $package->getUrl('/logo.png');
+    echo $pathPackage->getUrl('/logo.png');
     // result: /logo.png?v1
 
 Request Context Aware Assets
@@ -239,7 +239,7 @@ class can take into account the context of the current request::
     // result: /somewhere/static/images/logo.png?v1
 
     // Both "base path" and "base url" are ignored when using absolute path for asset
-    echo $package->getUrl('/logo.png');
+    echo $pathPackage->getUrl('/logo.png');
     // result: /logo.png?v1
 
 Now that the request context is set, the ``PathPackage`` will prepend the