staging: lustre: lnet: klnds: o2iblnd: fix null dereference on failed path in o2iblnd.c

If net is null and failed path is executed, dereference null may happen.
This patch fixes it. The following Coccinelle semantic patch was used.

@@
expression E, E1;
identifier f;
statement S1,S2,S3;
@@

* if (E == NULL)
{
  ... when != if (E == NULL) S1 else S2
      when != E = E1
* E->f
  ... when any
  return ...;
}
else S3

Signed-off-by: Jiayi Ye <yejiayily@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>