Update language to comply with Android's inclusive language guidance

See https://source.android.com/setup/contribute/respectful-code for reference

Bug: 162536543
Test: Build pass and boot
Change-Id: I5bf4d71e822dd3136f3fd7fd69d9df47b57320f6
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index ce45b7f..4f81836 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -160,8 +160,8 @@
     if (result != 0) {
         android_errorWriteLog(0x534e4554, "121035042");
 
-        int dummy = 0;
-        result = ioctl(mDriverFD, BINDER_SET_CONTEXT_MGR, &dummy);
+        int unused = 0;
+        result = ioctl(mDriverFD, BINDER_SET_CONTEXT_MGR, &unused);
     }
 
     if (result == -1) {