Bug 9873 - Quiet errors in the log from XSLT.pm

Bug 9873 - Quiet errors in the log from XSLT.pm

If XSLTResultsDisplay is enabled and items in your search results lack a
shelving location or a ccode errors will appear in the log complaining
of "uninitialized value in hash element." This patch adds a check on
these values to quiet the errors.

To test, find or create a record with items which have no shelving
location and/or no collection code. Perform a search the results for
which will include your record. Check for errors in the log.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Cleans up logs for result list quite a bit.
Passes all tests and QA script.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>