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>
diff --git a/arch/x86/um/tls_64.c b/arch/x86/um/tls_64.c
index f7ba462..d22363c 100644
--- a/arch/x86/um/tls_64.c
+++ b/arch/x86/um/tls_64.c
@@ -1,4 +1,4 @@
-#include "linux/sched.h"
+#include <linux/sched.h>
 
 void clear_flushed_tls(struct task_struct *task)
 {