doc: virtual: Fix typos in virtio-spec.txt

Correct spelling typo in documentation/virtual/virtio-spec.txt
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Acked-by: NRob Landley <rob@landley.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Documentation/virtual/virtio-spec.txt

@@ -1389,7 +1389,7 @@ segmentation, if both guests are amenable.
 
 Packets are transmitted by placing them in the transmitq, and
 buffers for incoming packets are placed in the receiveq. In each
-case, the packet itself is preceeded by a header:
+case, the packet itself is preceded by a header:
 
 struct virtio_net_hdr {
 
@@ -1631,7 +1631,7 @@ struct virtio_net_ctrl_mac {
 
 The device can filter incoming packets by any number of
 destination MAC addresses.[footnote:
-Since there are no guarentees, it can use a hash filter
+Since there are no guarantees, it can use a hash filter
 orsilently switch to allmulti or promiscuous mode if it is given
 too many addresses.
 ] This table is set using the class VIRTIO_NET_CTRL_MAC and the
@@ -1822,7 +1822,7 @@ the FLUSH and FLUSH_OUT types are equivalent, the device does not
 distinguish between them
 ]). If the device has VIRTIO_BLK_F_BARRIER feature the high bit
 (VIRTIO_BLK_T_BARRIER) indicates that this request acts as a
-barrier and that all preceeding requests must be complete before
+barrier and that all preceding requests must be complete before
 this one, and all following requests must not be started until
 this is complete. Note that a barrier does not flush caches in
 the underlying backend device in host, and thus does not serve as