Fix typo

Author: visitorckw

lkmpg.tex

@@ -1066,7 +1066,7 @@ \subsection{Registering A Device}
 int cdev_add(struct cdev *p, dev_t dev, unsigned count);
 \end{code}
 
-To find a example using the interface, you can see \verb|ioctl.c| described in section \ref{sec:device_files}.
+To find an example using the interface, you can see \verb|ioctl.c| described in section \ref{sec:device_files}.
 
 \subsection{Unregistering A Device}
 \label{sec:unregister_device}