Per feedback from nabijaczleweli, change the man pages slightly.

(For which I am very grateful, I'm at least 5 years out of
date on all the macros now.)

Signed-off-by: Sean Eric Fagan <kithrup@mac.com>

man/man8/zfs-send.8

@@ -40,7 +40,7 @@
 .Nm zfs
 .Cm send
 .Op Fl DLPRbcehnpsvw
-.Op Fl X Ar dataset[,dataset,...]
+.Op Fl X Ar dataset Ns Oo , Ns Ar dataset Ns ... Oc
 .Op Oo Fl I Ns | Ns Fl i Oc Ar snapshot
 .Ar snapshot
 .Nm zfs
@@ -141,7 +141,7 @@ If the
 flag is used to send encrypted datasets, then
 .Fl w
 must also be specified.
-.It Fl X , -exclude Ar dataset[,...]
+.It Fl X , -exclude Ar dataset Ns Oo , Ns Ar dataset Ns ... Oc
 When the
 .Fl R
 flag is given,