When makefs is invoked with '-t cd9660' to create an ISO 9660 filesystem
image, we currently write the string 'NetBSD' to the system ID field of the
primary volume descriptor.

The attached patch changes this to 'OpenBSD', in line with other commonly used
authoring software, E.G. mkhybrid.

Note that the system ID field in the PVD is not actually strictly defined as
the system that _authored_ the disc, but in practice this is what it has
become.

--- usr.sbin/makefs/cd9660.c	Tue Jan 11 05:34:32 2022
+++ usr.sbin/makefs/cd9660.c	Sat Jul 20 18:17:41 2024
@@ -218,7 +218,7 @@
 	memset(diskStructure->primaryDescriptor.abstract_file_id, 0x20,37);
 	memset(diskStructure->primaryDescriptor.bibliographic_file_id, 0x20,37);
 
-	strlcpy(diskStructure->primaryDescriptor.system_id,"NetBSD", sizeof(diskStructure->primaryDescriptor.system_id));
+	strlcpy(diskStructure->primaryDescriptor.system_id,"OpenBSD", sizeof(diskStructure->primaryDescriptor.system_id));
 
 	cd9660_defaults_set = 1;