wflinfo: if a parameter is not given, don't print NULL string
wflinfo: if a parameter is not given, don't print NULL string

If a parameter was not given for an option, for example:
    wflinfo --platform
Then we would try to print a NULL string.

Signed-off-by: Jordan Justen <a79006884ba9cf5f4f7fcbb92a15b208780d8c97@intel.com>
Signed-off-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@linux.intel.com>

evelikov/waffle,waffle-gl/waffle,maurossi/waffle,janesma/waffle,yinquan529/waffle-gl-waffle,janesma/waffle,waffle-gl/waffle,yinquan529/waffle-gl-waffle,chadversary/waffle,chadversary/waffle,fjhenigman/waffle,fjhenigman/waffle,dcbaker/waffle,chadversary/waffle,yinquan529/waffle-gl-waffle,maurossi/waffle,evelikov/waffle,fjhenigman/waffle,janesma/waffle,maurossi/waffle,dcbaker/waffle,waffle-gl/waffle,evelikov/waffle,waffle-gl/waffle,dcbaker/waffle