Revert "kretprobe: check re-registration of the same kretprobe earlier"

hulk inclusion
category: bugfix
bugzilla: 31369

-----------------------------------------------

This reverts commit ec02feff.
Following patche mainline has fixed this issue:
0188b878 ("kretprobe: Avoid re-registration of the same kretprobe earlier")
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NJian Cheng <cj.chengjian@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

kernel/kprobes.c

@@ -2137,11 +2137,6 @@ int register_kretprobe(struct kretprobe *rp)
 		}
 	}
 
-	/* Return error if it's being re-registered. */
-	ret = check_kprobe_rereg(&rp->kp);
-	if (ret)
-		return ret;
-
 	rp->kp.pre_handler = pre_handler_kretprobe;
 	rp->kp.post_handler = NULL;
 	rp->kp.fault_handler = NULL;