CLEANUP: lua: remove unneeded memset(0) after calloc()

No need for these memset() anymore, since calloc() was put there
to avoid them.
diff --git a/src/hlua.c b/src/hlua.c
index 3f7acf6..2d3f1e2 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -4364,9 +4364,6 @@
 	sck->kw[0].out_type = SMP_T_STR;
 	sck->kw[0].private = fcn;
 
-	/* End of array. */
-	memset(&sck->kw[1], 0, sizeof(struct sample_conv));
-
 	/* Register this new converter */
 	sample_register_convs(sck);
 
@@ -4425,9 +4422,6 @@
 	sfk->kw[0].val = 0;
 	sfk->kw[0].private = fcn;
 
-	/* End of array. */
-	memset(&sfk->kw[1], 0, sizeof(struct sample_fetch));
-
 	/* Register this new fetch. */
 	sample_register_fetches(sfk);
 
@@ -4647,9 +4641,6 @@
 		/* List head */
 		akl->list.n = akl->list.p = NULL;
 
-		/* End of array. */
-		memset(&akl->kw[1], 0, sizeof(*akl->kw));
-
 		/* action keyword. */
 		len = strlen("lua.") + strlen(name) + 1;
 		akl->kw[0].kw = calloc(1, len);