ssh: comment "fallthrough" in switch statement
Curl_pipeline_server_blacklisted: handle a NULL server name

Coverity CID 1215284. The server name is extracted with
Curl_copy_header_value() and passed in to this function, and
copy_header_value can actually can fail and return NULL.
curl_multi_remove_handle: remove dead code

Coverify CID 1157776. Removed a superfluous if() that always evaluated
true (and an else clause that never ran), and then re-indented the
function accordingly.
Curl_debug: document switch fallthroughs
parse_proxy: remove dead code.

Coverity CID 982331.
nonblock: call with (void) to show we ignore the return code

Coverity pointed out several of these.
Curl_sec_read_msg: spell out that we ignore return code

Coverity CID 1241947. Since if sscanf() fails, the previously set value
remains set.
choose_mech: fix return code

Coverity CID 1241950. The pointer is never NULL but it might point to
NULL.
getparameter: comment a switch FALLTHROUGH

Coverity CID 1061118. Point out that it is on purpose.
getparameter: remove dead code

Coverity CID 1061126. 'parse' will always be non-NULL here.
curl_schannel.c: Fixed possible memory or handle leak

First try to fix possible memory leaks, in this case:
Only connssl->ctxt xor onnssl->cred being initialized.