Make lwlocknames.h generated file less ugly

We can make the output look a bit better by aligning each lock's
definition, so add some padding space to achieve that.  This change
makes no practical difference, but casual onlookers will be less
distracted by (lack of) whitespace.

Author: Gurjeet Singh <gurjeet@singh.im>
Discussion: https://postgr.es/m/CABwTF4VxfwDtRV-H22_XK4XeDogaV-Vaobu+af5U=8ZAZn9ZZQ@mail.gmail.com

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

@@ -108,7 +108,8 @@ while (<$lwlocklist>)
 	$continue = ",\n";
 
 	# Add a "Lock" suffix to each lock name, as the C code depends on that
-	print $h "#define ${lockname}Lock (&MainLWLockArray[$lockidx].lock)\n";
+	printf $h "#define %-32s (&MainLWLockArray[$lockidx].lock)\n",
+	  $lockname . "Lock";
 }
 
 die