Load option with short device path for boot vars

The boot variables automatically generated for removable medias
should be with short form of device path without device nodes.
This is a requirement for the case that a removable media is
plugged into a different port but is still able to work with the
existing boot variables.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 993bb11..a40762c 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -368,6 +368,7 @@
 		struct efi_load_option lo;
 		char buf[BOOTMENU_DEVICE_NAME_MAX];
 		struct efi_device_path *device_path;
+		struct efi_device_path *short_dp;
 
 		ret = efi_search_protocol(volume_handles[i], &efi_guid_device_path, &handler);
 		if (ret != EFI_SUCCESS)
@@ -384,6 +385,11 @@
 		p = dev_name;
 		utf8_utf16_strncpy(&p, buf, strlen(buf));
 
+		/* prefer to short form device path */
+		short_dp = efi_dp_shorten(device_path);
+		if (short_dp)
+			device_path = short_dp;
+
 		lo.label = dev_name;
 		lo.attributes = LOAD_OPTION_ACTIVE;
 		lo.file_path = device_path;