Update the doc about configuring the kernel using kleaf

Added missing -- separator.

Bug: 254927882
Test: N/A
Change-Id: I7be8b55bdd93f2637ab54401eaaef4b3c9c45f31
diff --git a/microdroid/kernel/README.md b/microdroid/kernel/README.md
index 38eca71..44f828c 100644
--- a/microdroid/kernel/README.md
+++ b/microdroid/kernel/README.md
@@ -39,12 +39,12 @@
 
 For ARM64
 ```bash
-tools/bazel run //common-modules/virtual-device:microdroid_aarch64_config menuconfig
+tools/bazel run //common-modules/virtual-device:microdroid_aarch64_config -- menuconfig
 ```
 
 For x86\_64
 ```bash
-tools/bazel run //common-modules/virtual-device:microdroid_x86_64_config menuconfig
+tools/bazel run //common-modules/virtual-device:microdroid_x86_64_config -- menuconfig
 ```
 
 ## How to update Microdroid kernel prebuilts