Docs - Fix metrics name in user tutorial (#651)

**Description**
In result-summary.md line 73-74, the example of kernel-launch used
metrics 'kernel-launch/event_overhead' and
'kernel-launch/wall_overhead'.

But in micro-benchmarks.md line 20-21, the metric names are described as
'kernel-launch/event_time' and ' kernel-launch/wall_time'.

Solution: Use identical metric names described in micro-benchmarks.md.

https://github.com/microsoft/superbenchmark/issues/649

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: hongtaozhang <hongtaozhang@microsoft.com>
Co-authored-by: Yifan Xiong <yifan.xiong@microsoft.com>

docs/user-tutorial/data-diagnosis.md

@@ -83,8 +83,8 @@ superbench:
       criteria: lambda x:x>0.05
       categories: KernelLaunch
       metrics:
-        - kernel-launch/event_overhead:\d+
-        - kernel-launch/wall_overhead:\d+
+        - kernel-launch/event_time:\d+
+        - kernel-launch/wall_time:\d+
     rule1:
     # Rule 1: If H2D_Mem_BW or D2H_Mem_BW test suffers > 5% downgrade, label it as defective
       function: variance

docs/user-tutorial/result-summary.md

@@ -70,8 +70,8 @@ superbench:
       aggregate: True
       categories: KernelLaunch
       metrics:
-        - kernel-launch/event_overhead
-        - kernel-launch/wall_overhead
+        - kernel-launch/event_time
+        - kernel-launch/wall_time
     nccl:
       statistics: mean
       categories: NCCL