Fix stupid off-by-one error in erase verification

As reported by Jody McIntyre. Thanks!

Corresponding to flashrom svn r389 and coreboot v2 svn r3894.

Signed-off-by: Peter Stuge <peter@stuge.se>
Acked-by: Peter Stuge <peter@stuge.se>
diff --git a/flashrom.c b/flashrom.c
index 26585fb..4d8614a 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -605,7 +605,7 @@
 			memcpy(buf, (const char *)flash->virtual_memory, size);
 		else
 			flash->read(flash, buf);
-		for (erasedbytes = 0; erasedbytes <= size; erasedbytes++)
+		for (erasedbytes = 0; erasedbytes < size; erasedbytes++)
 			if (0xff != buf[erasedbytes]) {
 				printf("FAILED!\n");
 				fprintf(stderr, "ERROR at 0x%08x: Expected=0xff, Read=0x%02x\n",