LU-17000 coverity: Fix use before null under pcc.c

LU-17000 coverity: Fix use before null under pcc.c

This patch fixes 'dereference before null' error reported
by coverity run.

CoverityID: 397538 ("Dereference before null"): pcc.c

Test-Parameters: trivial testlist=sanity-pcc
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Ic125f74b61e500e2184bde894aade7119b7a2899
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/52658
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>