Revert "Add manatee halt/poweroff/reboot logic."

This reverts commit 7a9bc4fbe5897a8b7f52218f4236bb3af604445b because we
now have a way for crosvm to signal the caller (hypervisor in this case)
whether the guest has requested restart or shutdown).

BUG=b:197259207
TEST="reboot", "poweroff" on brya-manatee.

Change-Id: Ibe85880fbd6fd13d36a50822ab38c4d33d5f33c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/upstart/+/3322110
Reviewed-by: Junichi Uekawa <uekawa@chromium.org>
Reviewed-by: Allen Webb <allenwebb@google.com>
Tested-by: Dmitry Torokhov <dtor@chromium.org>
Commit-Queue: Dmitry Torokhov <dtor@chromium.org>
diff --git a/configure.ac b/configure.ac
index 00d1b6f..4344865 100644
--- a/configure.ac
+++ b/configure.ac
@@ -78,15 +78,6 @@
 	AC_DEFINE(RESTORE_PATHS, [{"/dev", "/run"}], [Define restorecon paths])
 fi
 
-# Define a preprocessor value if building for a manatee guest.
-AC_ARG_ENABLE(manatee,
-	AS_HELP_STRING([--enable-manatee], [enable ManaTEE guest support]),
-	[], [enable_manatee=no])
-
-if test "x$enable_manatee" = "xyes" ; then
-	AC_DEFINE(ENABLE_MANATEE, 1, [Define if we support ManaTEE])
-fi
-
 # If this argument is set, it means that we want to generate and include the
 # global seccomp policy in Upstart.
 AC_ARG_WITH([seccomp-constants],
diff --git a/util/reboot.c b/util/reboot.c
index 4a2114f..fa2e863 100644
--- a/util/reboot.c
+++ b/util/reboot.c
@@ -66,10 +66,6 @@
 #define SHUTDOWN SBINDIR "/shutdown"
 #endif
 
-#ifdef ENABLE_MANATEE
-const char MANATEE_CLIENT[] = "/usr/bin/manatee";
-#endif
-
 
 /* Operation modes */
 enum {
@@ -232,32 +228,6 @@
 	/* Re-enable Control-Alt-Delete in case it breaks */
 	reboot (RB_ENABLE_CAD);
 
-#ifdef ENABLE_MANATEE
-	int val = fork ();
-	if (val == 0) {
-		const char *flag;
-		/* Do the syscall */
-		switch (mode) {
-		case REBOOT:
-			nih_info (_("Rebooting"));
-			flag = "--reboot";
-			break;
-		case HALT:
-			nih_info (_("Halting"));
-			flag = "--halt";
-			break;
-		case POWEROFF:
-			nih_info (_("Powering off"));
-			flag = "--poweroff";
-			break;
-		}
-		const char *manatee_args[] = { MANATEE_CLIENT, flag };
-		execv (manatee_args[0], manatee_args);
-	} else {
-		waitpid (val, NULL, 0);
-	}
-#endif
-
 	/* Do the syscall */
 	switch (mode) {
 	case REBOOT: