Windows: Use AFSLibExAllocatePool for library local

If the memory allocation is for an object that must be freed before
the afsredirlib.sys driver unloads, use the AFSLibExAllocatePoolWithTag
interface.   AFSExAllocatePoolWithTag allocates the memory from
afsredir.sys which prevents Verifier from being used to detect leaks.

Change-Id: I3e384ff2da069a594d2cafe7b4b1a9bb942cbd08
Reviewed-on: http://gerrit.openafs.org/9852
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>
Windows: AFSLibExFreePool*() macros

Introduce the AFSLibExFreePool() and AFSLibExFreePoolWithTag() macros
which simply call ExFreePool() and ExFreePoolWithTag().

The prefix AFSLib indicates that memory allocated by
AFSLibExAllocatePoolWithTag() must be freed before unloading.
AFSExFreePool*() cannot be used because that is a pointer to a
function provided by AFSRedir.sys which may not be assigned when
memory must be freed.

The only time that ExFreePool() should be used is if the memory was
allocated by a system function.

Change-Id: If56b762d2b6d857dbe415171401d64ca10a1e9ea
Reviewed-on: http://gerrit.openafs.org/9853
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
Tested-by: Jeffrey Altman <jaltman@your-file-system.com>