Revert "[IA64] Unwire set/get_robust_list"

This reverts commit 26362554.

Jakub Jelinek provided the missing futex_atomic_cmpxchg_inatomic()
function, so now it should be safe to re-enable these syscalls.
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/entry.S

@@ -1605,8 +1605,8 @@ sys_call_table:
 	data8 sys_ni_syscall			// 1295 reserved for ppoll
 	data8 sys_unshare
 	data8 sys_splice
-	data8 sys_ni_syscall			// reserved for set_robust_list
-	data8 sys_ni_syscall			// reserved for get_robust_list
+	data8 sys_set_robust_list
+	data8 sys_get_robust_list
 	data8 sys_sync_file_range		// 1300
 	data8 sys_tee
 	data8 sys_vmsplice

include/asm-ia64/unistd.h

@@ -286,7 +286,8 @@
 /* 1294, 1295 reserved for pselect/ppoll */
 #define __NR_unshare			1296
 #define __NR_splice			1297
-/* 1298, 1299 reserved for set_robust_list/get_robust_list */
+#define __NR_set_robust_list		1298
+#define __NR_get_robust_list		1299
 #define __NR_sync_file_range		1300
 #define __NR_tee			1301
 #define __NR_vmsplice			1302