bug#7618: man mktemp/[deprecated] clarification

[jidanni]

man mktemp
       -p DIR use DIR as a prefix; implies -t [deprecated]

       -t     interpret TEMPLATE as a single file name component, relative to a 
directory: $TMPDIR, if  set;
              else the directory specified via -p; else /tmp [deprecated]

It is not clear what is deprecated, -p, or both. Move [deprecated]
closer to the front of the sentence.

Or add a DEPRECATED OPTIONS section.

Also I know the info page says why, but at

       -u, --dry-run
              do not create anything; merely print a name (unsafe)

the reader thinks 'why, will it grind up my filesystem?'
If --dry-run is unsafe, then I'd hate to try --wet-run.

Say (unsafe to use for ....).