Move unimplemented fn reset before ctx cleanup

Signed-off-by: Brenden Blanco <bblanco@gmail.com>

src/cc/bpf_module.cc

@@ -124,10 +124,6 @@ static StatusTuple unimplemented_snprintf(char *, size_t, const void *) {
 }
 
 BPFModule::~BPFModule() {
-  engine_.reset();
-  rw_engine_.reset();
-  ctx_.reset();
-
   for (auto &v : tables_) {
     v->key_sscanf = unimplemented_sscanf;
     v->leaf_sscanf = unimplemented_sscanf;
@@ -135,6 +131,10 @@ BPFModule::~BPFModule() {
     v->leaf_snprintf = unimplemented_snprintf;
   }
 
+  engine_.reset();
+  rw_engine_.reset();
+  ctx_.reset();
+
   ts_->DeletePrefix(Path({id_}));
 }