Remove old define that was duplicating asm/unistd.h information.

Remove old define that was duplicating asm/unistd.h information.

This was for __NR_ioprio_set which is a syscall without a glibc
interface.  Since the define is already done in asm/unistd.h
for our architectures we no longer need to have it in corewatcher.
Signed-off-by: William Douglas <william.douglas@intel.com>