Fix a few typos in comments

- trough -> through

MFC after:	1 week

share/man/man4/ng_macfilter.4

@@ -45,7 +45,7 @@ address.
 .Pp
 This processing is done when traffic flows from the
 .Dq ether
-hook trough
+hook through
 .Nm macfilter
 to one of the outgoing hooks.
 Outbound hooks can be added to and remove from

sys/netinet/sctp_ss_functions.c

@@ -583,7 +583,7 @@ sctp_ss_prio_set_value(struct sctp_tcb *stcb, struct sctp_association *asoc,
 
 /*
  * Fair bandwidth algorithm.
- * Maintains an equal troughput per stream.
+ * Maintains an equal throughput per stream.
  */
 static void
 sctp_ss_fb_clear(struct sctp_tcb *stcb, struct sctp_association *asoc,

sys/netpfil/ipfw/nat64/nat64_translate.c

@@ -722,7 +722,7 @@ nat64_icmp6_reflect(struct mbuf *m, uint8_t type, uint8_t code, uint32_t mtu,
 	/*
 	 * Move pkthdr from original mbuf. We should have initialized some
 	 * fields, because we can reinject this mbuf to netisr and it will
-	 * go trough input path (it requires at least rcvif should be set).
+	 * go through input path (it requires at least rcvif should be set).
 	 * Also do M_ALIGN() to reduce chances of need to allocate new mbuf
 	 * in the chain, when we will do M_PREPEND() or make some type of
 	 * tunneling.

sys/sys/soundcard.h

@@ -484,7 +484,7 @@ struct sysex_info {
  * This structure is also used with ioctl(SNDCTL_PGMR_IFACE) which allows
  * a patch manager daemon to read and write device parameters. This
  * ioctl available through /dev/sequencer also. Avoid using it since it's
- * extremely hardware dependent. In addition access trough /dev/sequencer
+ * extremely hardware dependent. In addition access through /dev/sequencer
  * may confuse the patch manager daemon.
  */