Don't print 168^W143 lines of help when someone makes a typo.

Print actual usage messages in most cases.

Add --help and --version.

Bug: http://b/28054087
Test: manual
Change-Id: I39c1cb7a84f52e0c35d24f140ec55c3a181283fb
diff --git a/adb/bugreport.cpp b/adb/bugreport.cpp
index 9b59d05..b7e76a6 100644
--- a/adb/bugreport.cpp
+++ b/adb/bugreport.cpp
@@ -182,11 +182,8 @@
     DISALLOW_COPY_AND_ASSIGN(BugreportStandardStreamsCallback);
 };
 
-// Implemented in commandline.cpp
-int usage();
-
 int Bugreport::DoIt(TransportType transport_type, const char* serial, int argc, const char** argv) {
-    if (argc > 2) return usage();
+    if (argc > 2) return usage("usage: adb bugreport [PATH]");
 
     // Gets bugreportz version.
     std::string bugz_stdout, bugz_stderr;