Documentation/ABI/testing/sysfs-ibft: fix a typo

Correct a sentence in Documentation/ABI/testing/sysfs-ibft.
Signed-off-by: WANG Chao <chaowang@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/ABI/testing/sysfs-ibft

@@ -20,4 +20,4 @@ Date:		November 2007
 Contact:	Konrad Rzeszutek <ketuzsezr@darnok.org>
 Description:	The /sys/firmware/ibft/ethernetX directory will contain
 		files that expose the iSCSI Boot Firmware Table NIC data.
-		This can this can the IP address, MAC, and gateway of the NIC.
+		Usually this contains the IP address, MAC, and gateway of the NIC.