app/test: fix build switches to enable cmdline tests
There were 2 typos since these commits (in 1.6.0 releases):
21a7f4e264 fix build without librte_cmdline
cac6d08c8b replace --use-device option by --pci-whitelist and --vdev
In makefiles, the build options are prefixed with CONFIG_RTE_
but in .c file, it is only RTE_.
These typos were disabling cmdline unit tests and test of "--vdev eth_ring" option.
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>