Check for HOSTDELETED before h_Hold_r

Check for HOSTDELETED before h_Hold_r

A few places h_Hold_r a host and later drop and reacquire H_LOCK without
checking if the hostFlags contains HOSTDELETED. This can cause a race
with h_TossStuff_r where we later reference a host that is about to be
freed or already has been freed.

Add checks for HOSTDELETED in these places, and skip over the deleted
hosts.

FIXES 126454

Reviewed-on: http://gerrit.openafs.org/1305
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit b8c3c6add90ea3face9a16ff04a1024be3d8f32d)

Change-Id: I9e67465b3dac6db8626fee03823ed63a680beaad
Reviewed-on: http://gerrit.openafs.org/1366
Tested-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>