Remove unused variable in generate-lwlocknames.pl.

Oversight in commit da952b415f.

Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aHpOgwuFQfcFMZ/B%40ip-10-97-1-34.eu-west-3.compute.internal

src/backend/storage/lmgr/generate-lwlocknames.pl

@@ -10,7 +10,6 @@ use Getopt::Long;
 my $output_path = '.';
 
 my $lastlockidx = -1;
-my $continue = "\n";
 
 GetOptions('outdir:s' => \$output_path);
 
@@ -102,10 +101,8 @@ while (<$lwlocklist>)
 	while ($lastlockidx < $lockidx - 1)
 	{
 		++$lastlockidx;
-		$continue = ",\n";
 	}
 	$lastlockidx = $lockidx;
-	$continue = ",\n";
 
 	# Add a "Lock" suffix to each lock name, as the C code depends on that
 	printf $h "#define %-32s (&MainLWLockArray[$lockidx].lock)\n",