Description: lib/syscall: fix syscall registers retrieval on 32-bit platforms
References:
 https://talosintelligence.com/vulnerability_reports/TALOS-2020-1211
Notes:
 carnil> Commit fixes 631b7abacd02 ("ptrace: Remove maxargs from
 carnil> task_current_syscall()") in 5.1-rc4. Fixed in 5.9.14 for
 carnil> v5.9.y.
Bugs:
upstream: released (5.10-rc7) [4f134b89a24b965991e7c345b9a4591821f7c2a6]
5.10-upstream-stable: N/A "Fixed before branch point"
4.19-upstream-stable: N/A "Vulnerable code not present"
4.9-upstream-stable: N/A "Vulnerable code not present"
sid: released (5.9.15-1)
4.19-buster-security: N/A "Vulnerable code not present"
4.9-stretch-security: N/A "Vulnerable code not present"