efi_loader: export efi_dp_shorten()

Rename function shorten_path() to efi_dp_shorten() and export it.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 110d8ae..1ffcdfc 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -725,7 +725,8 @@
 #define EFI_LOADER_BOUNCE_BUFFER_SIZE (64 * 1024 * 1024)
 #endif
 
-
+/* shorten device path */
+struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp);
 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp);
 int efi_dp_match(const struct efi_device_path *a,
 		 const struct efi_device_path *b);
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index dc787b4..ddd5f13 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -122,20 +122,25 @@
 	}
 }
 
-/*
+/**
+ * efi_dp_shorten() - shorten device-path
+ *
  * We can have device paths that start with a USB WWID or a USB Class node,
  * and a few other cases which don't encode the full device path with bus
  * hierarchy:
  *
- *   - MESSAGING:USB_WWID
- *   - MESSAGING:USB_CLASS
- *   - MEDIA:FILE_PATH
- *   - MEDIA:HARD_DRIVE
- *   - MESSAGING:URI
+ * * MESSAGING:USB_WWID
+ * * MESSAGING:USB_CLASS
+ * * MEDIA:FILE_PATH
+ * * MEDIA:HARD_DRIVE
+ * * MESSAGING:URI
  *
  * See UEFI spec (section 3.1.2, about short-form device-paths)
+ *
+ * @dp:		original devie-path
+ * @Return:	shortened device-path or NULL
  */
-static struct efi_device_path *shorten_path(struct efi_device_path *dp)
+struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp)
 {
 	while (dp) {
 		/*
@@ -189,7 +194,7 @@
 				}
 			}
 
-			obj_dp = shorten_path(efi_dp_next(obj_dp));
+			obj_dp = efi_dp_shorten(efi_dp_next(obj_dp));
 		} while (short_path && obj_dp);
 	}