This commit is the final batch of #3360’s `ATTRIBUTE_FORMAT` process,
covering various insignificant (as in, requires few-to-no
changes in addition to gaining this attribute) functions.
One of the main focus of this PR is to enable GCC `-Wformat` (by tagging
`ATTRIBUTE_FORMAT`) on ALL `my_snprintf` utilities. To be throughout,
functions that delegate to `my_vsnprintf` must also inherit this
attribute because `-Wformat` doesn’t trace argument across call stacks.
c8783757d6