cgi: avoid warning after exec

Found with mod_perl2 (as it overrides exit).

diff --git a/public-inbox.cgi b/public-inbox.cgi
index da87d2c34800b487cb0ff2d7dc77d5d25bd09d3c..56040676f6ae1142a1b133a3ce2c8a80c741af81 100755 (executable)
--- a/public-inbox.cgi
+++ b/public-inbox.cgi
@@ -155,8 +155,7 @@ sub mid2blob {
        defined $pid or die "fork failed: $!\n";
        if ($pid == 0) {
                open STDERR, '>', '/dev/null'; # ignore errors
-               exec @cmd;
-               exit 1;
+               exec @cmd or die "exec failed: $!\n";
        } else {
                my $blob = eval { local $/; <$fh> };
                close $fh;