sparse pointer use of zero as null

Get rid of sparse related warnings from places that use integer as NULL
pointer.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index 2f2b686..3dec003 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1028,7 +1028,7 @@
 		}
 		if (buffer_new(&dummy)) {
 			J_ASSERT(create != 0);
-			J_ASSERT(handle != 0);
+			J_ASSERT(handle != NULL);
 
 			/*
 			 * Now that we do not always journal data, we should