Revert "avb_tests: allow 0 or 1 for the selector"

We're still building DVT firmware, so reverting for now.

This reverts commit 60ebf01b3c15fbb67b10df64c2ad347a8c311f9f.

Change-Id: Ib28c2bd172ca5f96753631a4481cd616896d2b85
diff --git a/src/avb_tests.cc b/src/avb_tests.cc
index b6be4c4..32ff5ef 100644
--- a/src/avb_tests.cc
+++ b/src/avb_tests.cc
@@ -747,7 +747,7 @@
   ASSERT_LE(sizeof(data), len);
   ASSERT_NO_ERROR(code, "");
   EXPECT_NE(0ULL, nonce);
-  EXPECT_LE(selector, (uint32_t)ResetToken::CURRENT);
+  EXPECT_EQ((uint32_t)ResetToken::CURRENT, selector);
   EXPECT_EQ(32UL, len);
   // We didn't set a device id.
   EXPECT_EQ(0, memcmp(data, empty, sizeof(empty)));