Do not read the flash chip twice in verification mode

Kyösti Mälkki noticed that we unnecessarily read the flash chip twice when
called with --verify. The first one is the mandatory read before everything
(to be able to detect the seriousness of errors), but the second one is not
necessary because we can just use the former for the comparison.

This introduces a small output change: previously we printed ERASE or
VERIFY depending on the callee. This special case has been dropped
because it is unnecessary to print it (and wrong for the verification
function to need to know why it is verifying exactly).
If an erase fails we mention that fact explicitly already, similar for verify.

Corresponding to flashrom svn r1619.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/jedec.c b/jedec.c
index d8532c6..7bc9133 100644
--- a/jedec.c
+++ b/jedec.c
@@ -410,7 +410,7 @@
 
 	dst = d;
 	src = s;
-	failed = verify_range(flash, src, start, page_size, NULL);
+	failed = verify_range(flash, src, start, page_size);
 
 	if (failed && tried++ < MAX_REFLASH_TRIES) {
 		msg_cerr("retrying.\n");