Consistently use 'queueing' instead of 'queuing'. Both spellings are

correct, but the former seems to be preferred.  This makes all of the
section-4 manual pages consistent in this respect.

share/man/man4/ahc.4

@@ -105,7 +105,7 @@ and
 .Pp
 Driver features include support for twin and wide busses,
 fast, ultra or ultra2 synchronous transfers depending on controller type,
-tagged queuing, SCB paging, and target mode.
+tagged queueing, SCB paging, and target mode.
 .Pp
 Memory mapped I/O can be enabled for PCI devices with the
 .Dq Dv AHC_ALLOW_MEMIO
@@ -213,7 +213,7 @@ operations.
 .Sq Bayonet
 style Scatter Gather Engine - Improves S/G prefetch performance.
 .It
-Queuing Registers - Allows queuing of new transactions without pausing the
+Queuing Registers - Allows queueing of new transactions without pausing the
 sequencer.
 .It
 Multiple Target IDs - Allows the controller to respond to selection as a

share/man/man4/da.4

@@ -123,7 +123,7 @@ setting the
 The
 .Nm
 device driver will take full advantage of the SCSI feature known as tagged
-queuing.  Tagged queuing allows the device to process multiple transactions
+queueing.  Tagged queueing allows the device to process multiple transactions
 concurrently, often re-ordering them to reduce the number and length of
 seeks.  To ensure that transactions to distant portions of the media,
 which may be deferred indefinitely by servicing requests nearer the current

share/man/man4/netgraph.4

@@ -140,7 +140,7 @@ created at the time they are connected, and breaking an edge by
 removing either hook destroys both hooks.
 .It
 A hook can be set into a state where incoming packets are always queued
-by the input queuing system, rather than being delivered directly. This
+by the input queueing system, rather than being delivered directly. This
 is used when the two joined nodes need to be decoupled, e.g. if they are
 running at different processor priority levels. (spl)
 .It
@@ -336,7 +336,7 @@ hooks, and the links have been made, the nodes get a chance to
 find out who their peer is across the link and can then decide to reject
 the connection. Tear-down is automatic. This is also the time at which
 a node may decide whether to set a particular hook (or its peer) into
-.Em queuing
+.Em queueing
 mode.
 .It Destruction of a hook
 The node is notified of a broken connection. The node may consider some hooks

share/man/man4/sym.4

@@ -97,7 +97,7 @@ Driver features include support for wide SCSI busses and fast10, fast20,
 fast40 and fast80-dt synchronous data transfers depending on controller
 capabilities.
 It also provides generic SCSI features such as tagged command
-queuing and auto-request sense.
+queueing and auto-request sense.
 This driver is configured by default
 for a maximum of 446 outstanding commands per bus, 8 LUNs per target
 and 64 tagged tasks per LUN.