[cpp] Missing return statement in string_view::copy

[intrigus-lgtm]

Hey, there is a missing return statement in the string_view::copy function:

esbmc/src/cpp/library/string_view

Lines 64 to 67 in fb01095

	size_t copy(char *dest, size_t count, size_t pos = 0) const
	{
	memcpy(dest, str + pos, std::min(count, len - pos));
	}