doc: Fix typo in doucmentations

Correct typo (double words) in documentations.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/fb/fbcon.txt b/Documentation/fb/fbcon.txt
index 99ea58e..4a9739a 100644
--- a/Documentation/fb/fbcon.txt
+++ b/Documentation/fb/fbcon.txt
@@ -150,7 +150,7 @@
 
 C. Attaching, Detaching and Unloading
 
-Before going on on how to attach, detach and unload the framebuffer console, an
+Before going on how to attach, detach and unload the framebuffer console, an
 illustration of the dependencies may help.
 
 The console layer, as with most subsystems, needs a driver that interfaces with