docs/sysfs: add missing word to sysfs attribute explanation

Add the obvious missing word.

Signed-off-by: Shaun Zinck <shaun.zinck@gmail.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt
index 4b5ca26..4598ef7 100644
--- a/Documentation/filesystems/sysfs.txt
+++ b/Documentation/filesystems/sysfs.txt
@@ -51,7 +51,7 @@
 attributes.
 
 Attributes should be ASCII text files, preferably with only one value
-per file. It is noted that it may not be efficient to contain only
+per file. It is noted that it may not be efficient to contain only one
 value per file, so it is socially acceptable to express an array of
 values of the same type.