rbd: nuke copy_token()

It's been largely superseded by dup_token() and unused for over
2 years, identified by cppcheck.
Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
[idryomov@redhat.com: changelog]
Signed-off-by: Ilya Dryomov <idryomov@redhat.com>

drivers/block/rbd.c

@@ -4770,36 +4770,6 @@ static inline size_t next_token(const char **buf)
 	return strcspn(*buf, spaces);   /* Return token length */
 }
 
-/*
- * Finds the next token in *buf, and if the provided token buffer is
- * big enough, copies the found token into it.  The result, if
- * copied, is guaranteed to be terminated with '\0'.  Note that *buf
- * must be terminated with '\0' on entry.
- *
- * Returns the length of the token found (not including the '\0').
- * Return value will be 0 if no token is found, and it will be >=
- * token_size if the token would not fit.
- *
- * The *buf pointer will be updated to point beyond the end of the
- * found token.  Note that this occurs even if the token buffer is
- * too small to hold it.
- */
-static inline size_t copy_token(const char **buf,
-				char *token,
-				size_t token_size)
-{
-        size_t len;
-
-	len = next_token(buf);
-	if (len < token_size) {
-		memcpy(token, *buf, len);
-		*(token + len) = '\0';
-	}
-	*buf += len;
-
-        return len;
-}
-
 /*
  * Finds the next token in *buf, dynamically allocates a buffer big
  * enough to hold a copy of it, and copies the token into the new