n_gsm.c: removed duplicated #includes

drivers/char/n_gsm.c: linux/timer.h is included more than once.
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/n_gsm.c

@@ -43,7 +43,6 @@
 #include <linux/sched.h>
 #include <linux/interrupt.h>
 #include <linux/tty.h>
-#include <linux/timer.h>
 #include <linux/ctype.h>
 #include <linux/mm.h>
 #include <linux/string.h>