test/eeed8b54e0df-test: define RWF_NOWAIT if we don't have it

Older installs/distros don't have this in fs.h.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/test/eeed8b54e0df-test.c b/test/eeed8b54e0df-test.c
index 17018a2..9083d3e 100644
--- a/test/eeed8b54e0df-test.c
+++ b/test/eeed8b54e0df-test.c
@@ -13,6 +13,10 @@
 
 #define BLOCK	4096
 
+#ifndef RWF_NOWAIT
+#define RWF_NOWAIT	8
+#endif
+
 static int get_file_fd(void)
 {
 	ssize_t ret;