Address const issues in preparation for libcxx rebase.

Change-Id: I4eccc1b5a70da9dd325e1a7e10ab0a3fe588c03f
diff --git a/adb/socket.h b/adb/socket.h
index 9eb1b19..4acdf4a 100644
--- a/adb/socket.h
+++ b/adb/socket.h
@@ -118,7 +118,7 @@
 namespace internal {
 
 #if ADB_HOST
-char* skip_host_serial(const char* service);
+char* skip_host_serial(char* service);
 #endif
 
 }  // namespace internal