Remove receiving of unused return value

[JohnnySavages]

Found by Linux Verification Center (linuxtesting.org) with SVACE.

CLA: trivial

[mattcaswell]

Agree trivial

[tom-cosgrove-arm]

Wouldn't a better fix be to actually check the result of BIO_snprintf() and behave (abort?) accordingly, rather than just ignore the error? We're going to perform file operations on the output of BIO_snprintf(), so if the buffer's aren't filled there could be some weird filenames!

[JohnnySavages]

Wouldn't a better fix be to actually check the result of BIO_snprintf() and behave (abort?) accordingly, rather than just ignore the error? We're going to perform file operations on the output of BIO_snprintf(), so if the buffer's aren't filled there could be some weird filenames!

Actually function cannot cause an "insufficient buffer" failure due to check higher. In the case of an incorrect string literal specifying the format, the use of the information specified in the buffer will fail, for which there is a check below.

Nevertheless, it might still be better to add a check for return codes. idk.
And if so, should I use assert everywhere?

[shahsb]

Wouldn't a better fix be to actually check the result of BIO_snprintf() and behave (abort?) accordingly, rather than just ignore the error? We're going to perform file operations on the output of BIO_snprintf(), so if the buffer's aren't filled there could be some weird filenames!

I agree with @tom-cosgrove-arm

[openssl-machine]

This PR is in a state where it requires action by @openssl/committers but the last update was 30 days ago

[tom-cosgrove-arm]

While it would definitely be better to add checks, rather than just omit them, the rest of the code in apps/ appears to be no better. Even in tests I see a TEST_true(BIO_snprintf(...)) (and that's insane, since BIO_snprintf() returns number of chars written or -1 for error, so is presumably almost never going to return zero).

So I'm now approving this PR as-is - any further fixing would need to have a wider scope

[openssl-machine]

This pull request is ready to merge

[t8m]

Merged to the master branch. Thank you for your contribution.