W39V040B: Flag Erase/Write as bad.

Chip has now been properly tested in both my Jetway J7F5M and my EPIA-SP
(known good board). Erase and write fail.

Reported by Arvid Brodin <arvidb@kth.se>.

Signed-off-by: Luc Verhaegen <libv@skynet.be>

Index: flashchips.c
===================================================================
--- flashchips.c	(revision 641)
+++ flashchips.c	(working copy)
@@ -2881,7 +2881,7 @@
 		.model_id	= W_39V040B,
 		.total_size	= 512,
 		.page_size	= 64*1024,
-		.tested		= TEST_OK_PREW,
+		.tested		= TEST_OK_PR | TEST_BAD_ERASE | TEST_BAD_WRITE,
 		.probe		= probe_jedec,
 		.probe_timing	= 10, 
 		.erase		= erase_chip_jedec,