lib/base64: fix copy-pasted @padding doc in base64_decode()

The @padding kernel-doc for base64_decode() says "whether to append '='
padding characters", which was copy-pasted from base64_encode().  In the
decode context, it controls whether the input is expected to include
padding, not whether to append it.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Josh Law <[email protected]>
Reviewed-by: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

lib/base64.c

@@ -122,7 +122,7 @@ EXPORT_SYMBOL_GPL(base64_encode);
  * @src: the string to decode.  Doesn't need to be NUL-terminated.
  * @srclen: the length of @src in bytes
  * @dst: (output) the decoded binary data
- * @padding: whether to append '=' padding characters
+ * @padding: whether the input is expected to include '=' padding characters
  * @variant: which base64 variant to use
  *
  * Decodes a string using the selected Base64 variant.