resolve windows warnings and add sanity check with PKCS12 parse

wolfcrypt/src/integer.c

@@ -4223,6 +4223,10 @@ static int mp_div_d (mp_int * a, mp_digit b, mp_int * c, mp_digit * d)
       q.used = a->used;
       q.sign = a->sign;
   }
+  else {
+      mp_init(&q); /* initialize to help static analysis */
+  }
+
 
   w = 0;
   for (ix = a->used - 1; ix >= 0; ix--) {