scripted-diff: [test] Use g_rng/m_rng directly

-BEGIN VERIFY SCRIPT-

 # Use m_rng in unit test files
 ren() { sed -i "s:\<$1\>:$2:g" $( git grep -l "$1" src/test/*.cpp src/wallet/test/*.cpp src/test/util/setup_common.cpp ) ; }
 ren InsecureRand32                m_rng.rand32
 ren InsecureRand256               m_rng.rand256
 ren InsecureRandBits              m_rng.randbits
 ren InsecureRandRange             m_rng.randrange
 ren InsecureRandBool              m_rng.randbool
 ren g_insecure_rand_ctx           m_rng
 ren g_insecure_rand_ctx_temp_path g_rng_temp_path

-END VERIFY SCRIPT-

src/test/script_tests.cpp

@@ -127,7 +127,7 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
 
     // Verify that removing flags from a passing test or adding flags to a failing test does not change the result.
     for (int i = 0; i < 16; ++i) {
-        uint32_t extra_flags(InsecureRandBits(16));
+        uint32_t extra_flags(m_rng.randbits(16));
         uint32_t combined_flags{expect ? (flags & ~extra_flags) : (flags | extra_flags)};
         // Weed out some invalid flag combinations.
         if (combined_flags & SCRIPT_VERIFY_CLEANSTACK && ~combined_flags & (SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS)) continue;