cxl/cdat: Remove redundant gp_port initialization

gp_port is already pointed to the grandparent port during its definition,
remove a redundant code to let gp_port point to the grandparent port
again.

Signed-off-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Link: https://patch.msgid.link/20250211062054.300108-1-ming.li@zohomail.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: MingLi-4

drivers/cxl/core/cdat.c

@@ -658,7 +658,6 @@ static int cxl_endpoint_gather_bandwidth(struct cxl_region *cxlr,
 	if (IS_ERR(perf))
 		return PTR_ERR(perf);
 
-	gp_port = to_cxl_port(parent_port->dev.parent);
 	*gp_is_root = is_cxl_root(gp_port);
 
 	/*