event/octeontx: fix build with icc

event/octeontx: fix build with icc

build error:
.../drivers/event/octeontx/ssovf_worker.c(212):
error #592: variable "get_work0" is used before its value is set
        RTE_SET_USED(get_work0);
        ^

.../drivers/event/octeontx/ssovf_worker.c(213):
error #592: variable "get_work1" is used before its value is set
        RTE_SET_USED(get_work1);
        ^
For x86 these variables set but not used, move macros below
where values assigned.

Fixes: f61808eaa9ad ("event/octeontx: add start function")
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>