[PATCH v2] s390: fix build error for sys_call_table_emu

[Xiaoming Ni]

Build error on s390:
	arch/s390/kernel/entry.o: in function `sys_call_table_emu':
	>> (.rodata+0x1288): undefined reference to `__s390_'

In commit ("All arch: remove system call sys_sysctl")
 148  common	fdatasync		sys_fdatasync			sys_fdatasync
-149  common	_sysctl			sys_sysctl			compat_sys_sysctl
+149  common	_sysctl			sys_ni_syscall
 150  common	mlock			sys_mlock			sys_mlock

After the patch is integrated, there is a format error in the generated
arch/s390/include/generated/asm/syscall_table.h:
	SYSCALL(sys_fdatasync, sys_fdatasync)
	SYSCALL(sys_ni_syscall,) /* cause build error */
	SYSCALL(sys_mlock,sys_mlock)

According to the guidance of Heiko Carstens, use "-" to fill the empty system call
 Similarly, modify tools/perf/arch/s390/entry/syscalls/syscall.tbl.

Fixes: ("All arch: remove system call sys_sysctl")
Fixes: https://lore.kernel.org/linuxppc-dev/20200616030734.87257-1-nixiaoming@xxxxxxxxxx/
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Xiaoming Ni <nixiaoming@xxxxxxxxxx>

changes in v2:
	use "-" to fill the empty system call

v1: https://lore.kernel.org/lkml/20200618110320.104013-1-nixiaoming@xxxxxxxxxx/
---
 arch/s390/kernel/syscalls/syscall.tbl           | 2 +-
 tools/perf/arch/s390/entry/syscalls/syscall.tbl | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index f17aaf6fe5de..04c34c2ed916 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -138,7 +138,7 @@
 146  common	writev			sys_writev			compat_sys_writev
 147  common	getsid			sys_getsid			sys_getsid
 148  common	fdatasync		sys_fdatasync			sys_fdatasync
-149  common	_sysctl			sys_ni_syscall
+149  common	_sysctl			-				-
 150  common	mlock			sys_mlock			sys_mlock
 151  common	munlock			sys_munlock			sys_munlock
 152  common	mlockall		sys_mlockall			sys_mlockall
diff --git a/tools/perf/arch/s390/entry/syscalls/syscall.tbl b/tools/perf/arch/s390/entry/syscalls/syscall.tbl
index 0193f9b98753..29144b79a49d 100644
--- a/tools/perf/arch/s390/entry/syscalls/syscall.tbl
+++ b/tools/perf/arch/s390/entry/syscalls/syscall.tbl
@@ -138,7 +138,7 @@
 146  common	writev			sys_writev			compat_sys_writev
 147  common	getsid			sys_getsid			sys_getsid
 148  common	fdatasync		sys_fdatasync			sys_fdatasync
-149  common	_sysctl			sys_ni_syscall
+149  common	_sysctl			-				-
 150  common	mlock			sys_mlock			compat_sys_mlock
 151  common	munlock			sys_munlock			compat_sys_munlock
 152  common	mlockall		sys_mlockall			sys_mlockall
-- 
2.27.0