Fix incorrect logging in sdp_discovery

In two locations in sdp_discovery.cc, log statements use structures that
may, in exceptional cases, have been freed by preceding calls.  This can
lead to use after free and potentially to security vulnerabilities.

Use local variables instead.

Bug: 375408314
Bug: 375409435
Test: m libbluetooth
Test: researcher POC
Flag: EXEMPT trivial logic fix
Ignore-AOSP-First: security
Tag: #security
Change-Id: I76e1ffa1fe463a5858d61d025447d855ff6b5b84