Check for defines the right way

I keep forgetting that autoconf says '#define FOO 0' rather than '#undef
FOO'...

diff --git a/nbd-server.c b/nbd-server.c
index e894f4ca35df103c78609591dc8ee7cd38a9ef90..4bbf41303ff24525304f105c6c09928ea0e29536 100644 (file)
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -83,7 +83,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <fcntl.h>
-#ifdef HAVE_FALLOC_PH
+#if HAVE_FALLOC_PH
 #include <linux/falloc.h>
 #endif
 #include <arpa/inet.h>