des-compat-test: Fix out of bounds memory read.

ChangeLog

 2014-06-04  Niels Möller  <nisse@lysator.liu.se>
 
+	* testsuite/des-compat-test.c (test_main): Fixed out of bounds
+	memory read, reported by Nikos Mavrogiannopoulos.
+
 	* nettle-write.h: Include <stddef.h>, fixing compilation on
 	freebsd.
 

testsuite/des-compat-test.c

@@ -358,7 +358,7 @@ test_main(void)
 			printf("Key error %2d:%d\n",i+2,j);
 			err=1;
 			}
-		if ((j=des_key_sched(&key_data[i+2],ks3)) != 0)
+		if (i+2 < NUM_TESTS && (j=des_key_sched(&key_data[i+2],ks3)) != 0)
 			{
 			printf("Key error %2d:%d\n",i+3,j);
 			err=1;