Remove a bogus memcmp in range_should_be_prefix()

Remove a bogus memcmp in range_should_be_prefix()

range_should_be_prefix() currently always fails. The reason for this
is that OpenSSL commit 42d7d7dd incorrectly moved a memcmp() out of
an assertion.  As a consequence, the library emits and accepts
incorrectly encoded ipAddrBlock extensions since it will never detect
ranges that MUST be encoded as a prefix according to RFC 3779, 2.2.3.7.

The return -1 from this memcmp() indicates to the callers that the
range should be expressed as a range, so callers must check beforehand
that min <= max to be able to fail. Thus, remove this memcmp() and
add a check to make_addressRange(), the only caller that didn't already
ensure that min <= max.

This fixes the noisy output in regress/lib/libcrypto/x509/rfc3779.

ok inoguchi jsing