n_tracerouter: stop including <asm-generic/bug>

<asm-generic/bug> contains the default implementation of BUG() and friends,
which architectures may decide to use.  The proper way to get them is
<linux/bug.h>, so use that.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/tty/n_tracerouter.c

@@ -34,7 +34,7 @@
 #include <linux/string.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
-#include <asm-generic/bug.h>
+#include <linux/bug.h>
 #include "n_tracesink.h"
 
 /*