A few hand-written function names in printf strings could be updated to use `__func__`

[thnkslprpt]

Checklist

• [x] I reviewed the Contributing Guide.
• [x] I performed a cursory search to see if the bug report is relevant, not redundant, nor in conflict with other tickets.

Describe the bug There are a few remaining locations in PSP that use hand-written function names in the printf() message strings.

Code snips https://github.com/nasa/PSP/blob/6fceb13c1dc433f0943fb41511acd1f9a96916f3/fsw/pc-rtems/src/cfe_psp_support.c#L83 https://github.com/nasa/PSP/blob/6fceb13c1dc433f0943fb41511acd1f9a96916f3/fsw/pc-linux/src/cfe_psp_support.c#L131

Expected behavior Use the __func__ predefined identifier where possible to lower future dependencies to updating hand-written comments.

Reporter Info Avi Weiss @thnkslprpt