cloned_binary: switch from #error to #warning for SYS_memfd_create
We shouldn't refuse to build on architectures just because we don't know
what the syscall number of memfd_create(2) is. In addition, use the
correct defined(...) macros for ppc64 (these are the ones glibc uses).
Fixes: ("nsenter: hard-code memfd_create(2) syscall numbers")
# define SYS_memfd_create 385
# elif defined(__aarch64__)
# define SYS_memfd_create 279
-# elif defined(__ppc__) || defined(__ppc64__)
+# elif defined(__ppc__) || defined(__PPC64__) || defined(__powerpc64__)
# define SYS_memfd_create 360
# elif defined(__s390__) || defined(__s390x__)
# define SYS_memfd_create 350
# else
-# error "unknown architecture -- cannot hard-code SYS_memfd_create"
+# warning "unknown architecture -- cannot hard-code SYS_memfd_create"
# endif
# endif
#endif
