efi_loader: fix uninitialized variable bug in efi_set_load_options()

Check for efi_search_protocol() failure before dereferencing "handler"
to avoid a crash.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
diff --git a/lib/efi_loader/efi_load_options.c b/lib/efi_loader/efi_load_options.c
index 3cfddee..5f62184 100644
--- a/lib/efi_loader/efi_load_options.c
+++ b/lib/efi_loader/efi_load_options.c
@@ -31,10 +31,10 @@
 	efi_status_t ret;
 
 	ret = efi_search_protocol(handle, &efi_guid_loaded_image, &handler);
-	loaded_image_info = handler->protocol_interface;
 	if (ret != EFI_SUCCESS)
 		return EFI_INVALID_PARAMETER;
 
+	loaded_image_info = handler->protocol_interface;
 	loaded_image_info->load_options = load_options;
 	loaded_image_info->load_options_size = load_options_size;