um: don't include kern.h unless it's needed

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

arch/um/drivers/ssl.c

@@ -15,7 +15,6 @@
 #include "line.h"
 #include "ssl.h"
 #include "chan_kern.h"
-#include "kern.h"
 #include "init.h"
 #include "irq_user.h"
 #include "mconsole_kern.h"

arch/um/drivers/ubd_kern.c

@@ -46,7 +46,6 @@
 #include "asm/tlbflush.h"
 #include "mem_user.h"
 #include "kern_util.h"
-#include "kern.h"
 #include "mconsole_kern.h"
 #include "init.h"
 #include "irq_user.h"