makedoc.c: Warning when -Wall

Hi

I noticed in tbe build output that makedoc.c is compiled without -Wall. I'm
not sure how to add that to the Makefile but when I built it by hand, it
turned up this single warning. I am not sure where the parentheses should
go to address the warning and ensure this is doing what's intended. It
doesn't help that I don't know what the intent is. :).

../newlib-cygwin/newlib/doc/makedoc.c: In function ‘courierize’:
../newlib-cygwin/newlib/doc/makedoc.c:574:6: warning: suggest parentheses
around ‘&&’ within ‘||’ [-Wparentheses]
      && (at(tos, idx+1) == '.')
      ^
Thanks.

--joel