USB: Documentation/usb/ehci.txt: Checkpatch cleanup

Documentation/usb/ehci.txt:12: ERROR: trailing whitespace

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/Documentation/usb/ehci.txt b/Documentation/usb/ehci.txt
index 1536b7e..9dcafa7 100644
--- a/Documentation/usb/ehci.txt
+++ b/Documentation/usb/ehci.txt
@@ -9,7 +9,7 @@
     - "Low Speed" 1.5 Mbit/sec
 
 USB 1.1 only addressed full speed and low speed.  High speed devices
-can be used on USB 1.1 systems, but they slow down to USB 1.1 speeds. 
+can be used on USB 1.1 systems, but they slow down to USB 1.1 speeds.
 
 USB 1.1 devices may also be used on USB 2.0 systems.  When plugged
 into an EHCI controller, they are given to a USB 1.1 "companion"