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/file.c b/arch/um/os-Linux/file.c
index b049a63..c17bd6f 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -13,7 +13,7 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
-#include "os.h"
+#include <os.h>
 
 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
 {