* util/cairo-trace/trace.c: Fix compilation on Solaris (no setenv).

--- util/cairo-trace/trace.c.old	2010-09-02 13:38:56.000000000 +0200
+++ util/cairo-trace/trace.c	2010-11-23 15:57:11.540600643 +0100
@@ -811,7 +811,7 @@ _init_logfile (void)
 	    return FALSE;
 	}
 
-	setenv ("CAIRO_TRACE_FD", "-1", 1);
+	putenv (strdup ("CAIRO_TRACE_FD=-1"));
 	goto done;
     }
 
@@ -832,7 +832,7 @@ _init_logfile (void)
 
 	filename = buf;
 
-	setenv ("CAIRO_TRACE_FD", "-1", 1);
+	putenv (strdup ("CAIRO_TRACE_FD=-1"));
     }
 
     logfile = fopen (filename, "wb");