efi: Drop all uses of efi_call_XX() wrappers

Now that GCC can generate function calls using the correct calling
convention for us, we can stop using the efi_call_XX() wrappers, and
just dereference the function pointers directly.

This avoids the untyped variadic wrapper routines, which means better
type checking for the method calls.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/commands/efi/lsefi.c

@@ -108,8 +108,9 @@ grub_cmd_lsefi (grub_command_t cmd __attribute__ ((unused)),
 	  grub_efi_print_device_path (dp);
 	}
 
-      status = efi_call_3 (grub_efi_system_table->boot_services->protocols_per_handle,
-			   handle, &protocols, &num_protocols);
+      status = grub_efi_system_table->boot_services->protocols_per_handle (handle,
+									   &protocols,
+									   &num_protocols);
       if (status != GRUB_EFI_SUCCESS) {
 	grub_printf ("Unable to retrieve protocols\n");
 	continue;