fixup! Switch to a single malloc call

Author: real-or-random

src/ecmult_gen_impl.h

@@ -108,7 +108,7 @@ static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_cont
 static void secp256k1_ecmult_gen_context_finalize_memcpy(secp256k1_ecmult_gen_context *dst, const secp256k1_ecmult_gen_context *src) {
 #ifndef USE_ECMULT_STATIC_PRECOMPUTATION
     if (src->prec != NULL) {
-        /* We cast to void* first to suppress a -Wcast-align warning in clang. */
+        /* We cast to void* first to suppress a -Wcast-align warning. */
         dst->prec = (secp256k1_ge_storage (*)[64][16])(void*)((unsigned char*)dst + ((unsigned char*)src->prec - (unsigned char*)src));
     }
 #else

src/ecmult_impl.h

@@ -344,11 +344,12 @@ static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, void *
 
 static void secp256k1_ecmult_context_finalize_memcpy(secp256k1_ecmult_context *dst, const secp256k1_ecmult_context *src) {
     if (src->pre_g != NULL) {
-        dst->pre_g = (secp256k1_ge_storage (*)[])((unsigned char*)dst + ((unsigned char*)(src->pre_g) - (unsigned char*)src));
+        /* We cast to void* first to suppress a -Wcast-align warning. */
+        dst->pre_g = (secp256k1_ge_storage (*)[])(void*)((unsigned char*)dst + ((unsigned char*)(src->pre_g) - (unsigned char*)src));
     }
 #ifdef USE_ENDOMORPHISM
     if (src->pre_g_128 != NULL) {
-        dst->pre_g_128 = (secp256k1_ge_storage (*)[])((unsigned char*)dst + ((unsigned char*)(src->pre_g_128) - (unsigned char*)src));
+        dst->pre_g_128 = (secp256k1_ge_storage (*)[])(void*)((unsigned char*)dst + ((unsigned char*)(src->pre_g_128) - (unsigned char*)src));
     }
 #endif
 }