man: Add note about corosync not using name option

Signed-off-by: Jan Friesse <jfriesse@redhat.com>

man/corosync.conf.5

@@ -657,7 +657,7 @@ to guide establishing a nominal (self-)identification for each node
 in case neither respective
 .B ringX_addr
 specifies a network hostname nor other means are available/effective
-in this process.
+in this process. Option is not used by Corosync itself.
 
 .PP
 Within the