SQUASHME: more PR feedback

Author: andozw

core/src/checks/wycheproof_checks.c

@@ -123,15 +123,16 @@ static bool should_ignore_failure(size_t vector_label) {
 
 // runs tests against each wycheproof vector and reports any failures
 int verify_wycheproof(void) {
+  // inline the include to have the smallest scope possible for the variables defined in the include file.
   #include "wycheproof/ecdsa_secp256k1_sha256_bitcoin_test.h"
 
   int failures = 0;
   for (size_t t = 0; t < SECP256K1_ECDSA_WYCHEPROOF_NUMBER_TESTVECTORS; t++) {
     // The json test vectors are 1-indexed.
     const size_t vector_label = t + 1;
-    const unsigned char *msg;
-    const unsigned char *der_sig;
-    const unsigned char *pk;
+    const uint8_t *msg = NULL;
+    const uint8_t *der_sig = NULL;
+    const uint8_t *pk = NULL;
     const ecdsa_curve *curve = &secp256k1;
     uint8_t sig[64] = {0};
     curve_point pub;