staging: lustre: coding style fixes found by checkpatch.pl

The patch removes "WARNING: Prefer using '"%s...", __func__'
to using 'xxxxxxxx', this function's name, in a string" warnings
reported by checkpatch.pl script.

Signed-off-by: Simo Koskinen <koskisoft@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>