efi_loader: remove redundant statement

ascii2unicode() always ends the u16 string with '\0'.
Remove redundant assignment.

Add description for efi_str_to_u16() and ascii2unicode().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/efi_loader.h

@@ -411,7 +411,15 @@ efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
 	(((_dp)->type == DEVICE_PATH_TYPE_##_type) && \
 	 ((_dp)->sub_type == DEVICE_PATH_SUB_TYPE_##_subtype))
 
-/* Convert strings from normal C strings to uEFI strings */
+/**
+ * ascii2unicode() - convert ASCII string to UTF-16 string
+ *
+ * A zero terminated ASCII string is converted to a zero terminated UTF-16
+ * string. The output buffer must be preassigned.
+ *
+ * @unicode:	preassigned output buffer for UTF-16 string
+ * @ascii:	ASCII string to be converted
+ */
 static inline void ascii2unicode(u16 *unicode, const char *ascii)
 {
 	while (*ascii)

lib/efi_loader/efi_device_path_to_text.c

@@ -17,6 +17,15 @@
 const efi_guid_t efi_guid_device_path_to_text_protocol =
 		EFI_DEVICE_PATH_TO_TEXT_PROTOCOL_GUID;
 
+/**
+ * efi_str_to_u16() - convert ASCII string to UTF-16
+ *
+ * A u16 buffer is allocated from pool. The ASCII string is copied to the u16
+ * buffer.
+ *
+ * @str:	ASCII string
+ * Return:	UTF-16 string. NULL if out of memory.
+ */
 static u16 *efi_str_to_u16(char *str)
 {
 	efi_uintn_t len;
@@ -29,7 +38,6 @@ static u16 *efi_str_to_u16(char *str)
 	if (ret != EFI_SUCCESS)
 		return NULL;
 	ascii2unicode(out, str);
-	out[len - 1] = 0;
 	return out;
 }