utils: Cover for missing newline after BUG() messages

utils: Cover for missing newline after BUG() messages

Relieve callers from having to suffix their messages with a newline
escape sequence, have the macro append it to the format string instead.

This is mostly a fix for (the many) calls to BUG() without a newline
suffix. Adjust the previously correct ones since they emit an extra
newline now.

Signed-off-by: Phil Sutter <phil@nwl.cc>