Fix implicit-fallthrough warnings.

Test: make checkbuild
Bug: 112564944
Change-Id: I91f1b040480cbf199580982b3ed0975ce77104b3
diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index 21a9bce..b37b7fd 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -2645,7 +2645,7 @@
             // Should not happen during first time configuration.
             ALOGE("Cannot start a device in MODE_POINTER_RELATIVE, starting in MODE_POINTER");
             mParameters.mode = Parameters::MODE_POINTER;
-            // fall through.
+            [[fallthrough]];
         case Parameters::MODE_POINTER:
             mSource = AINPUT_SOURCE_MOUSE;
             mXPrecision = 1.0f;