fix preadv2 and pwritev2 syscall numbers on x32 for linux v4.8

the numbers were wrong in musl, but they were also wrong in the kernel
and got fixed in v4.8 commit 3ebfd81f7fb3e81a754e37283b7f38c62244641a

arch/x32/bits/syscall.h.in

@@ -280,8 +280,6 @@
 #define __NR_membarrier (0x40000000 + 324)
 #define __NR_mlock2 (0x40000000 + 325)
 #define __NR_copy_file_range (0x40000000 + 326)
-#define __NR_preadv2 (0x40000000 + 327)
-#define __NR_pwritev2 (0x40000000 + 328)
 
 #define __NR_rt_sigaction (0x40000000 + 512)
 #define __NR_rt_sigreturn (0x40000000 + 513)
@@ -317,4 +315,6 @@
 #define __NR_io_setup (0x40000000 + 543)
 #define __NR_io_submit (0x40000000 + 544)
 #define __NR_execveat (0x40000000 + 545)
+#define __NR_preadv2 (0x40000000 + 546)
+#define __NR_pwritev2 (0x40000000 + 547)