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/um/os-Linux/time.c b/arch/um/os-Linux/time.c
index 0748fe0..fac388c 100644
--- a/arch/um/os-Linux/time.c
+++ b/arch/um/os-Linux/time.c
@@ -8,8 +8,8 @@
 #include <signal.h>
 #include <time.h>
 #include <sys/time.h>
-#include "kern_util.h"
-#include "os.h"
+#include <kern_util.h>
+#include <os.h>
 #include "internal.h"
 
 int set_interval(void)