fix adb {forward,reverse} --no-rebind

adb forward --no-rebind (and the matching reverse command) seem to have
been broken by d98ca8a92f6bf81a351472f36fac9a04a402327e. I fixed-up the
string parsing and also fixed the error message not to include
strerror(errno) since that does not apply because it is an
application-level error that doesn't have anything to do with the
OS/libc.

Change-Id: Iba7286283bfcf1782076355edcd9c355c0a0edfd
Signed-off-by: Spencer Low <CompareAndSwap@gmail.com>
diff --git a/adb.cpp b/adb.cpp
index 97ce125..aa9ef55 100644
--- a/adb.cpp
+++ b/adb.cpp
@@ -770,12 +770,12 @@
         if (android::base::StartsWith(service, "killforward:")) {
             kill_forward = true;
             service += 12;
+        } else {
+            service += 8;   // skip past "forward:"
             if (android::base::StartsWith(service, "norebind:")) {
                 no_rebind = true;
                 service += 9;
             }
-        } else {
-            service += 8;
         }
 
         std::vector<std::string> pieces = android::base::Split(service, ";");
@@ -824,7 +824,7 @@
             message = android::base::StringPrintf("cannot bind to socket: %s", strerror(errno));
             break;
           case INSTALL_STATUS_CANNOT_REBIND:
-            message = android::base::StringPrintf("cannot rebind existing socket: %s", strerror(errno));
+            message = android::base::StringPrintf("cannot rebind existing socket");
             break;
           case INSTALL_STATUS_LISTENER_NOT_FOUND:
             message = android::base::StringPrintf("listener '%s' not found", service);