grub-lakitu: CHROMIUM: hook "linux" command

The grub.cfg template of Chrome OS uses "linux" command. In order to
use that as is, and also in order to prevent the bootloader from
loading unsigned linux kernels,  we change "linux" command to
"linuxefi" command.

BUG=b:69569602
TEST=TBD

Change-Id: I57e952b96b2a45c554597920a6bf7da50cc98ad6
Reviewed-on: https://chromium-review.googlesource.com/945905
Reviewed-by: Edward Jee <edjee@google.com>
Commit-Queue: Edward Jee <edjee@google.com>
Tested-by: Edward Jee <edjee@google.com>
Trybot-Ready: Edward Jee <edjee@google.com>

grub-lakitu/include/grub/command.h

diff --git a/grub-lakitu/include/grub/command.h b/grub-lakitu/include/grub/command.h
index eee4e84..9ba63af 100644
--- a/grub-lakitu/include/grub/command.h
+++ b/grub-lakitu/include/grub/command.h
@@ -109,6 +109,8 @@
 static inline grub_command_t
 grub_command_find (const char *name)
 {
+  if (grub_strcmp ("linux", name) == 0)
+    name = "linuxefi";
   return grub_named_list_find (GRUB_AS_NAMED_LIST (grub_command_list), name);
 }