libc: replace 0 with NULL for pointers.

While here also cleanup some surrounding code; particularly
drop some malloc() casts.

Found with devel/coccinelle.

Reviewed by:	bde (previous version - all new bugs are mine)

2 files changed, 3 insertions, 3 deletions

diff --git a/lib/libc/db/hash/hash.c b/lib/libc/db/hash/hash.c
index fc4e50e..f7b1427 100644
--- a/lib/libc/db/hash/hash.c
+++ b/lib/libc/db/hash/hash.c
@@ -771,7 +771,7 @@ next_bucket:
 		if (__big_keydata(hashp, bufp, key, data, 1))
 			return (ERROR);
 	} else {
-		if (hashp->cpage == 0)
+		if (hashp->cpage == NULL)
 			return (ERROR);
 		key->data = (u_char *)hashp->cpage->page + bp[ndx];
 		key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
diff --git a/lib/libc/db/hash/hash_buf.c b/lib/libc/db/hash/hash_buf.c
index e79e7b3..5c62a2c 100644
--- a/lib/libc/db/hash/hash_buf.c
+++ b/lib/libc/db/hash/hash_buf.c
@@ -245,7 +245,7 @@ newbuf(HTAB *hashp, u_int32_t addr, BUFHEAD *prev_bp)
 			 */
 			for (xbp = bp; xbp->ovfl;) {
 				next_xbp = xbp->ovfl;
-				xbp->ovfl = 0;
+				xbp->ovfl = NULL;
 				xbp = next_xbp;
 
 				/* Check that ovfl pointer is up date. */
@@ -350,7 +350,7 @@ __buf_free(HTAB *hashp, int do_free, int to_disk)
 void
 __reclaim_buf(HTAB *hashp, BUFHEAD *bp)
 {
-	bp->ovfl = 0;
+	bp->ovfl = NULL;
 	bp->addr = 0;
 	bp->flags = 0;
 	BUF_REMOVE(bp);