Deobfuscate cleanup path in clnt_bck_create(..)
Similar to r300836, cl and ct will always be non-NULL as they're allocated
using the mem_alloc routines, which always use malloc(..., M_WAITOK) .
Deofuscating the cleanup path fixes a leak where if cl was NULL and
ct was not, ct would not be free'd, and also removes a duplicate test for
cl not being NULL.
MFC after: 1 week
Reported by: Coverity
CID: 1229999
Sponsored by: EMC / Isilon Storage Division