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/block/cfq-iosched.txt b/Documentation/block/cfq-iosched.txt
index 9887f04..f3bc729 100644
--- a/Documentation/block/cfq-iosched.txt
+++ b/Documentation/block/cfq-iosched.txt
@@ -69,7 +69,7 @@
 group_idle
 -----------
 This parameter forces idling at the CFQ group level instead of CFQ
-queue level. This was introduced after after a bottleneck was observed
+queue level. This was introduced after a bottleneck was observed
 in higher end storage due to idle on sequential queue and allow dispatch
 from a single queue. The idea with this parameter is that it can be run with
 slice_idle=0 and group_idle=8, so that idling does not happen on individual