!120 Fix uprobes rbtree usage

Merge Pull Request from: @x56Jason 
 
This PR is to cherry-pick upstream fix for commit c6bc9bd06dff ("rbtree, uprobes: Use rbtree helpers")

BPFTrace Issue
#I5RUM5

== Tests

1, run bpftrace /usr/share/bpftrace/tools/bashreadline.bt without the fix, we can see the core dump

2, Apply the fix, and run bpftrace /usr/share/bpftrace/tools/bashreadline.bt, the issue disappears.

== Known Issue
N/A

== Default config change
N/A 
 
Link:https://gitee.com/openeuler/kernel/pulls/120 
Reviewed-by: Xu Kuohai <xukuohai@huawei.com> 
Reviewed-by: Zheng Zengkai <zhengzengkai@huawei.com> 
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> 

kernel/events/uprobes.c

@@ -663,7 +663,7 @@ static struct uprobe *__find_uprobe(struct inode *inode, loff_t offset)
 	struct rb_node *node = rb_find(&key, &uprobes_tree, __uprobe_cmp_key);
 
 	if (node)
-		return __node_2_uprobe(node);
+		return get_uprobe(__node_2_uprobe(node));
 
 	return NULL;
 }