[PATCH 2/4] httpd/async: remove useless undef

[Eric Wong <e@80x24.org>]

Assigning `undef' to a scalar doesn't free it's memory,
we need to call `undef($var)' in the caller.  It's also
been pointless since we simplified ->async_pass in commit
b7fbffd1f8c12556 (httpd/async: get rid of ephemeral main_cb, 2019-12-25)
---
 lib/PublicInbox/HTTPD/Async.pm | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lib/PublicInbox/HTTPD/Async.pm b/lib/PublicInbox/HTTPD/Async.pm
index 9e592f47..75b3bd50 100644
--- a/lib/PublicInbox/HTTPD/Async.pm
+++ b/lib/PublicInbox/HTTPD/Async.pm
@@ -84,10 +84,6 @@ sub async_pass {
 	# *_wcb methods respond to ->write (and ->close), not ->print
 	$fh->write($$bref);
 
-	# we're done with this, free this memory up ASAP since the
-	# calls after this may use much memory:
-	$$bref = undef;
-
 	$self->{http} = $http;
 	$self->{fh} = $fh;
 }