Change error message "partial transfer" to "some files could not be

transferred".

I don't generally like changing that sort of thing, but I think this
one was a persistent source of confusion.

log.c

@@ -51,7 +51,7 @@ struct {
 	{ RERR_SIGNAL     , "received SIGUSR1 or SIGINT" }, 
 	{ RERR_WAITCHILD  , "some error returned by waitpid()" }, 
 	{ RERR_MALLOC     , "error allocating core memory buffers" }, 
-	{ RERR_PARTIAL    , "partial transfer" }, 
+	{ RERR_PARTIAL    , "some files could not be transferred" }, 
 	{ RERR_TIMEOUT    , "timeout in data send/receive" }, 
 	{ RERR_CMD_FAILED , "remote shell failed" },
 	{ RERR_CMD_KILLED , "remote shell killed" },