SC2320: false negative for printf

[e-kwsm]

For bugs

• Rule Id (if any, e.g. SC1000): SC2320
• My shellcheck version (shellcheck --version or 'online'): online
• I tried on shellcheck.net and verified that this is still a problem on the latest commit
• It's not reproducible on shellcheck.net, but I think that's because it's an OS, configuration or encoding issue

For new checks and feature suggestions

• shellcheck.net (i.e. the latest commit) currently gives no useful warnings about this
• I searched through https://github.com/koalaman/shellcheck/issues and didn't find anything related

Here's a snippet or screenshot that shows the problem:

#!/bin/sh
mycommand
# echo "Command exited with $?"       # OK, SC2320 detected
printf 'Command exited with %d\n' $?  # SC2320 NOT detected
if [ $? -ne 0 ]
then
  echo "Failed"
fi

Here's what shellcheck currently says:

Line 5	SC2181: Check exit code directly with e.g. 'if ! mycmd;', not indirectly with $?.

Here's what I wanted or expected to see:

+Line 5	SC2320: This $? refers to echo/printf, not a previous command. Assign to variable to avoid it being overwritten.
 Line 5	SC2181: Check exit code directly with e.g. 'if ! mycmd;', not indirectly with $?.