riscv: rename __NR_fstatat __NR_newfstatat

on riscv64 this syscall is called __NR_newfstatat
this helps the name match kernel UAPI for external
programs

arch/riscv64/bits/syscall.h.in

@@ -76,7 +76,7 @@
 #define __NR_splice 76
 #define __NR_tee 77
 #define __NR_readlinkat 78
-#define __NR_fstatat 79
+#define __NR_newfstatat 79
 #define __NR_fstat 80
 #define __NR_sync 81
 #define __NR_fsync 82