[dpdk-stable] [PATCH] eal/windows: fix pthreads macros return values

[Dmitry Kozlyuk]

Hi Tal,

Getting warnings from x86_64-w64-mingw32-gcc (GCC) 9.3.0:

../../../lib/librte_eal/common/eal_common_thread.c: In function ‘ctrl_params_free’:
../../../lib/librte_eal/windows/include/pthread.h:42:2: warning: value computed is not used [-Wunused-value]
   42 |  !DeleteSynchronizationBarrier(barrier)

Probably applies to other functions and may fire in combination with future
backported patches. Hopefully since 21.05 there will be new threading API.