Remove extern "C" barriers to using C++.

Change-Id: Ic046d6aa540738cb46b54531bc59ba3b47b0136d
diff --git a/adb_trace.h b/adb_trace.h
index ef5dc24..32b6ae4 100644
--- a/adb_trace.h
+++ b/adb_trace.h
@@ -23,10 +23,6 @@
 #include <stdio.h>
 #endif
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* define ADB_TRACE to 1 to enable tracing support, or 0 to disable it */
 #define  ADB_TRACE    1
 
@@ -34,7 +30,7 @@
  * forget to update the corresponding 'tags' table in
  * the adb_trace_init() function implemented in adb.c
  */
-typedef enum {
+enum AdbTrace {
     TRACE_ADB = 0,   /* 0x001 */
     TRACE_SOCKETS,
     TRACE_PACKETS,
@@ -47,7 +43,7 @@
     TRACE_SERVICES,
     TRACE_AUTH,
     TRACE_FDEVENT,
-} AdbTrace;
+} ;
 
 #if ADB_TRACE
 
@@ -148,8 +144,4 @@
 #  define  ADB_TRACING     0
 #endif /* ADB_TRACE */
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* __ADB_TRACE_H */