nios2: traced syscall does need to check the syscall number

stable inclusion
from stable-v5.10.138
commit 8d0118a027e3c9ab39e31b1fafdb7103922ef3c3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8d0118a027e3c9ab39e31b1fafdb7103922ef3c3



--------------------------------

commit 25ba820e upstream.

all checks done before letting the tracer modify the register
state are worthless...

Fixes: 82ed08dd ("nios2: Exception handling")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>