cxl: Destroy afu->contexts_idr on release of an afu

Destroy afu->contexts_idr on release of an afu, reclaiming the allocated
memory.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

drivers/misc/cxl/pci.c

@@ -551,6 +551,7 @@ static void cxl_release_afu(struct device *dev)
 
 	pr_devel("cxl_release_afu\n");
 
+	idr_destroy(&afu->contexts_idr);
 	kfree(afu);
 }