Initialise return values

src/accessor/grib_accessor_class_variable.cc

@@ -32,9 +32,9 @@ void grib_accessor_class_variable_t::init(grib_accessor* a, const long length, g
  grib_expression* expression = grib_arguments_get_expression(hand, args, 0);
  const char* p = 0;
  size_t len = 1;
- long l;
+ long l = 0;
  int ret = 0;
- double d;
+ double d = 0;
  self->cname = NULL;
 
  a->length = 0;