LINUX: replace BUG() call with osi_Panic() in osi_linux_free
If osi_linux_free fails, it printf's an error message, then calls BUG().
This is the sole open-coded call to BUG() in OpenAFS; all other calls
to BUG() are indirect via osi_Panic().
For consistency, eliminate this direct BUG() call by replacing the
printf and BUG() with an equivalent osi_Panic(). This also ensures that
the error messsage is logged as critical, and prefixed with "openafs:".
Change-Id: Id319dffa859308528a66991bbbc522ca49552d51
Reviewed-on: https://gerrit.openafs.org/14250
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: Benjamin Kaduk <kaduk@mit.edu>