trace: [bsd-user] Commandline arguments to control tracing

trace: [bsd-user] Commandline arguments to control tracing

[Changed const char *trace_file to char *trace_file since it's a
heap-allocated string that needs to be freed.  This type is also
returned by trace_opt_parse() and used in vl.c.

Also fixed coding style on for(;;) and else statement as suggested by
Eric Blake <[email protected]> since the patch modifies these lines or
close enough.
--Stefan]

Signed-off-by: Lluís Vilanova <[email protected]>
Message-id: 146860252322.30668.18276041739086338328[email protected]
Signed-off-by: Stefan Hajnoczi <[email protected]>