trusty: clear fuzzer's extra counters directly

The FuzzerDefs.h APIs are internal to the fuzzer and aren't available
when the fuzzer is built with a custom private libc++, so remove the
ExtraCountersBegin/ExtraCountersEnd assertions and inline the array
clearing.

Bug: 175635923
Bug: 303175229
Bug: 315079422
Test: m libtrusty_fuzz_utils trusty_gatekeeper_fuzzer
Change-Id: I1ca9d9867026ff6f8e494ac6026fb1314caab7d1
diff --git a/trusty/fuzz/counters.cpp b/trusty/fuzz/counters.cpp
index 65a3ba6..e730ec3 100644
--- a/trusty/fuzz/counters.cpp
+++ b/trusty/fuzz/counters.cpp
@@ -16,12 +16,12 @@
 
 #define LOG_TAG "trusty-fuzz-counters"
 
-#include <FuzzerDefs.h>
-
 #include <trusty/fuzz/counters.h>
 
 #include <android-base/logging.h>
+#include <assert.h>
 #include <log/log.h>
+#include <string.h>
 #include <trusty/coverage/coverage.h>
 #include <trusty/coverage/tipc.h>
 
@@ -45,9 +45,6 @@
         return;
     }
 
-    assert(fuzzer::ExtraCountersBegin());
-    assert(fuzzer::ExtraCountersEnd());
-
     volatile uint8_t* begin = NULL;
     volatile uint8_t* end = NULL;
     record_->GetRawCounts(&begin, &end);
@@ -66,9 +63,8 @@
     if (!record_->IsOpen()) {
         return;
     }
-
     record_->ResetCounts();
-    fuzzer::ClearExtraCounters();
+    memset_explicit(const_cast<uint8_t*>(counters), 0, sizeof(counters));
 }
 
 void ExtraCounters::Flush() {