um: get rid of pointless include "..." where include <...> will do

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/os-Linux/drivers/ethertap_kern.c

@@ -9,7 +9,7 @@
 #include <linux/init.h>
 #include <linux/netdevice.h>
 #include "etap.h"
-#include "net_kern.h"
+#include <net_kern.h>
 
 struct ethertap_init {
 	char *dev_name;