replace 'putstr' attribute with 'printf'

[Maik93]

This is due to braking changes on Agiodisc_t.

[traversaro]

Hi @Maik93 ! Gazebo Classic would need to continue to compile with older versions of graphviz, as those are the one available on many distribution on which Gazebo Classic is supported, so probably we may need to have some preprocessor logic to select which code to execute depending on the used graphviz version.

Furthermore, this specific change has been reverted (see https://gitlab.com/graphviz/graphviz/-/blob/a9c36efe4041cc16a54e834440e3a489eaa222e1/CHANGELOG.md#fixed) so probably the logic would need to have this piece of code just for graphviz 4.0.0, as the next release of graphviz will need again the old logic.

[acxz]

@traversaro thanks for commenting on this and providing more insight. In that case, it is prob best for us on archlinux to just use the previous graphviz with gazebo until 4.0.1 is released or manually patch the package on our end. It is prob not worth then to have a fix specifically for just an intermediate graphviz version in gazebo upstream.

[scpeters]

ok, I'll close this for now, but feel free to reopen if you feel that a change is warranted