6c delete .6 file on error

R=r
DELTA=1  (1 added, 0 deleted, 0 changed)
OCL=13785
CL=13785

src/cmd/cc/lex.c

@@ -244,6 +244,7 @@ compile(char *file, char **defs, int ndef)
 			errorexit();
 		}
 		Binit(&outbuf, c, OWRITE);
+		outfile = strdup(outfile);
 	}
 	newio();
 	first = 0;