drivers:staging:lustre Fixed sparse warning: plain integer as NULL pointer

Fixes these sparse warnings:
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:202:51: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:203:51: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:204:51: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:205:51: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:206:51: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:207:11: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:213:47: warning: Using plain integer as NULL pointer
drivers/staging/lustre/lustre/lmv/lproc_lmv.c:214:11: warning: Using plain integer as NULL pointer

Signed-off-by: John de la Garza <john@jjdev.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>