Fix an antipattern when using canUseTopic

remove redundant range checks that are checked in the fixed canUseTopic

code/modules/assembly/health.dm

@@ -91,7 +91,7 @@
 
 	var/mob/user = usr
 
-	if(!user.canUseTopic(user))
+	if(!user.canUseTopic(src))
 		usr << browse(null, "window=hscan")
 		onclose(usr, "hscan")
 		return
@@ -104,4 +104,4 @@
 		return
 
 	attack_self(user)
-	return
+	return