[doc] Fix illegal example code in trouble.texi

[Gabriel Dos Reis]

Mark Mitchell <mark@codesourcery.com> writes:

| Jonathan Wakely wrote:
| 
| >I sent this mail a couple of weeks ago, but omitted this list, sending
| >it to gcc-patches only - oops.
| >
| >http://gcc.gnu.org/ml/gcc-patches/2004-08/msg00849.html
| >
| >OK to commit on mainline? 3.4? 3.3?
| >
| OK for mainline and 3.4.

Same for 3.3.x

-- Gaby