devtools: check use of compiler attributes
devtools: check use of compiler attributes

The keyword __attribute__ will emit a warning,
because it is preferred to use or define a common __rte macro.
The centralized macros may help to control or workaround some compilers.

Signed-off-by: Thomas Monjalon <5f50a84c1fa3bcff146405017f36aec1a10a9e38@monjalon.net>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk