mboxgz: fix compiler parse error under under Perl 5.16.3

Perl 5.16.3 (and possibly older versions) fails with the
following errors (from CentOS7):

  Use of ?PATTERN? without explicit operator is deprecated
  Search pattern not terminated

diff --git a/lib/PublicInbox/MboxGz.pm b/lib/PublicInbox/MboxGz.pm
index 2a55447f84e873b7fedb0db4b969128856c7eb5a..1621cff8f3f99511fa20ff91469fdc14e32126d6 100644 (file)
--- a/lib/PublicInbox/MboxGz.pm
+++ b/lib/PublicInbox/MboxGz.pm
@@ -63,7 +63,7 @@ sub getline {
        # signal that we're done and can return undef next call:
        delete $self->{ctx};
        my $err = $gz->flush($buf, Z_FINISH);
-       $err == Z_OK ? $buf : gzip_fail($ctx, $err);
+       ($err == Z_OK) ? $buf : gzip_fail($ctx, $err);
 }
 
 sub close {} # noop