drop the deprecated "rc" binary

This binary is a copy of the openrc binary. Referring to it as rc was
deprecated in 2016, so we should be able to drop it at this point.

src/openrc/meson.build

@@ -6,12 +6,3 @@ executable('openrc',
   include_directories: [incdir, einfo_incdir, rc_incdir],
   install: true,
   install_dir: sbindir)
-
-executable('rc',
-  ['rc.c', 'rc-logger.c', misc_c, plugin_c, usage_c, version_h],
-  c_args : cc_branding_flags,
-  link_with: [libeinfo, librc],
-  dependencies: [dl_dep, util_dep],
-  include_directories: [incdir, einfo_incdir, rc_incdir],
-  install: true,
-  install_dir: sbindir)

src/openrc/rc.c

@@ -837,8 +837,6 @@ int main(int argc, char **argv)
 		}
 	}
 
-	if (strcmp(applet, "rc") == 0)
-		ewarn("rc is deprecated, please use openrc instead.");
 	newlevel = argv[optind++];
 	/* To make life easier, we only have the shutdown runlevel as
 	 * nothing really needs to know that we're rebooting.