Fix PRESUBMIT.py

A symbol used later in the function scope was mistakenly deleted.

Change-Id: I5b1412b300a45bf9fd852018ae1ef54c6a6a6964
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/84789
Commit-Queue: Rudolf Polzer <rpolzer@google.com>
Auto-Submit: Lily Chen <chlily@google.com>
Reviewed-by: Rudolf Polzer <rpolzer@google.com>

PRESUBMIT.py

diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 817a601..2f6dd4e 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -105,7 +105,6 @@
   Returns:
     List of presubmit errors.
   """
-  del output_api  # Unused.
   file_paths = []
   for affected_file in input_api.AffectedFiles(include_deletes=False):
     affected_file_path = affected_file.LocalPath()