lshal: emphasize HIDL in docs/output

Some IMs floating about this recently. For now, lshal is still HIDL
specific and binder-facing tools work with AIDL HALs.

It remains to be seen if lshal will be re-adapted for AIDL in the
future, or if some of the ideas here will be transfered to dumpsys and
this binary ultimately deprecated.

Bug: N/A
Test: lshal/lshal --help
Change-Id: I39be9533b44c085a0688eb39171a0a40f88067b2
diff --git a/cmds/lshal/Lshal.cpp b/cmds/lshal/Lshal.cpp
index 99cb93a..bc99f4d 100644
--- a/cmds/lshal/Lshal.cpp
+++ b/cmds/lshal/Lshal.cpp
@@ -59,7 +59,8 @@
 }
 
 void Lshal::usage() {
-    err() << "lshal: List and debug HALs." << std::endl << std::endl
+    err() << "lshal: List and debug HIDL HALs." << std::endl
+          << "   (for AIDL HALs, see `dumpsys`)" << std::endl << std::endl
           << "commands:" << std::endl;
 
     size_t nameMaxLength = 0;