Use libsodium's s < L check, instead checking that libsodium checks that.

src/gtest/main.cpp

@@ -1,8 +1,8 @@
 #include "gtest/gtest.h"
-#include "sodium.h"
+#include "crypto/common.h"
 
 int main(int argc, char **argv) {
-  assert(sodium_init() != -1);
+  assert(init_and_check_sodium() != -1);
   testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
 }