bump updater API version to 3; deprecate firmware update command

Remove support for the HTC-specific "firmware" update command and the
corresponding edify function write_firmware_update().  This
functionality is now done by an edify extension library that lives in
vendor/htc.

Change-Id: I80858951ff10ed8dfff98aefb796bef009e05efb
diff --git a/updater/updater.c b/updater/updater.c
index 1aa277c..2d16dee 100644
--- a/updater/updater.c
+++ b/updater/updater.c
@@ -39,9 +39,11 @@
     }
 
     char* version = argv[1];
-    if ((version[0] != '1' && version[0] != '2') || version[1] != '\0') {
-        // We support version "1" or "2".
-        fprintf(stderr, "wrong updater binary API; expected 1 or 2, got %s\n",
+    if ((version[0] != '1' && version[0] != '2' && version[0] != '3') ||
+        version[1] != '\0') {
+        // We support version 1, 2, or 3.
+        fprintf(stderr, "wrong updater binary API; expected 1, 2, or 3; "
+                        "got %s\n",
                 argv[1]);
         return 2;
     }
@@ -100,6 +102,7 @@
     UpdaterInfo updater_info;
     updater_info.cmd_pipe = cmd_pipe;
     updater_info.package_zip = &za;
+    updater_info.version = atoi(version);
 
     State state;
     state.cookie = &updater_info;