[SCSI] lpfc: check before dereference in lpfc_ct.c

If we fail to allocate mp->virt during the first while loop iteration,
mlist is still uninitialized, therefore we should check if before
dereferencing.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Acked-by: James Smart <James.Smart@Emulex.Com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>