Make the %s format (seconds since the epoch) work for a negative

number and when used with a zero-padded field width, e.g. %015s.

(my_strftime): Move the `do_number_sign_and_padding'
label so that it precedes the code to set `digits'.  Otherwise,
%0Ns wouldn't work.  Before this change, `date -d @-22 +%05s' would
print `00-22'.  Now, it prints `-0022', as it should.

lib/strftime.c

@@ -909,10 +909,10 @@ my_strftime (CHAR_T *s, size_t maxsize, const CHAR_T *format,
 	    }
 	  while (u_number_value != 0);
 
+	do_number_sign_and_padding:
 	  if (digits < width)
 	    digits = width;
 
-	do_number_sign_and_padding:
 	  if (negative_number)
 	    *--bufp = L_('-');