staging: lustre: Cleaning up unnecessary use of memset in conjunction with strncpy

Using memset before strncpy just to ensure a trailing null
character is an unnecessary double writing of a string

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>