cxl/region: decrement ->nr_targets on error in cxl_region_attach()

The ++ needs a match -- on the clean up path.  If the p->nr_targets
value gets to be more than 16 it leads to uninitialized data in
cxl_port_setup_targets().

drivers/cxl/core/region.c:995 cxl_port_setup_targets() error: uninitialized symbol 'eiw'.

Fixes: 27b3f8d1 ("cxl/region: Program target lists")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YuepCvUAoCtdpcoO@kiliSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/region.c

@@ -1218,12 +1218,14 @@ static int cxl_region_attach(struct cxl_region *cxlr,
 	if (p->nr_targets == p->interleave_ways) {
 		rc = cxl_region_setup_targets(cxlr);
 		if (rc)
-			goto err;
+			goto err_decrement;
 		p->state = CXL_CONFIG_ACTIVE;
 	}
 
 	return 0;
 
+err_decrement:
+	p->nr_targets--;
 err:
 	for (iter = ep_port; !is_cxl_root(iter);
 	     iter = to_cxl_port(iter->dev.parent))