Adb: use VLOG() to replace D() for verbose logging.

As there are too many D(), we can keep both VLOG() and D() now, and get
rid of D() gradually.

Change-Id: I2f1cb70bcab3e82c99fed939341d03f6b2216076
diff --git a/adb/commandline.cpp b/adb/commandline.cpp
index 4e93dee..8aad97d 100644
--- a/adb/commandline.cpp
+++ b/adb/commandline.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#define TRACE_TAG TRACE_ADB
+#define TRACE_TAG ADB
 
 #include "sysdeps.h"
 
@@ -1546,6 +1546,8 @@
     }
     else if (!strcmp(argv[0], "keygen")) {
         if (argc < 2) return usage();
+        // Always print key generation information for keygen command.
+        adb_trace_enable(AUTH);
         return adb_auth_keygen(argv[1]);
     }
     else if (!strcmp(argv[0], "jdwp")) {