Fix admin follow runtime (#43282)

Fixed a minor runtime caused by admins clicking a follow link while in
the lobby.

code/modules/admin/admin_verbs.dm

@@ -333,11 +333,12 @@ GLOBAL_PROTECT(admin_verbs_hideable)
 	set name = "Aghost"
 	if(!holder)
 		return
+	. = TRUE
 	if(isobserver(mob))
 		//re-enter
 		var/mob/dead/observer/ghost = mob
 		if(!ghost.mind || !ghost.mind.current) //won't do anything if there is no body
-			return
+			return FALSE
 		if(!ghost.can_reenter_corpse)
 			log_admin("[key_name(usr)] re-entered corpse")
 			message_admins("[key_name_admin(usr)] re-entered corpse")
@@ -346,6 +347,7 @@ GLOBAL_PROTECT(admin_verbs_hideable)
 		SSblackbox.record_feedback("tally", "admin_verb", 1, "Admin Reenter") //If you are copy-pasting this, ensure the 2nd parameter is unique to the new proc!
 	else if(isnewplayer(mob))
 		to_chat(src, "<font color='red'>Error: Aghost: Can't admin-ghost whilst in the lobby. Join or Observe first.</font>")
+		return FALSE
 	else
 		//ghostize
 		log_admin("[key_name(usr)] admin ghosted.")

code/modules/admin/topic.dm

@@ -930,8 +930,12 @@
 		var/atom/movable/AM = locate(href_list["adminplayerobservefollow"])
 
 		var/client/C = usr.client
+		var/can_ghost = TRUE
 		if(!isobserver(usr))
-			C.admin_ghost()
+			can_ghost = C.admin_ghost()
+
+		if(!can_ghost)
+			return
 		var/mob/dead/observer/A = C.mob
 		A.ManualFollow(AM)