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/jbd/transaction.c b/fs/jbd/transaction.c
index 0282deb..9841b1e 100644
--- a/fs/jbd/transaction.c
+++ b/fs/jbd/transaction.c
@@ -1172,7 +1172,7 @@
 	}
 
 	/* That test should have eliminated the following case: */
-	J_ASSERT_JH(jh, jh->b_frozen_data == 0);
+	J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
 
 	JBUFFER_TRACE(jh, "file as BJ_Metadata");
 	spin_lock(&journal->j_list_lock);
@@ -1522,7 +1522,7 @@
 
 	J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
 	if (jh->b_jlist != BJ_None)
-		J_ASSERT_JH(jh, transaction != 0);
+		J_ASSERT_JH(jh, transaction != NULL);
 
 	switch (jh->b_jlist) {
 	case BJ_None:
@@ -1591,11 +1591,11 @@
 	if (buffer_locked(bh) || buffer_dirty(bh))
 		goto out;
 
-	if (jh->b_next_transaction != 0)
+	if (jh->b_next_transaction != NULL)
 		goto out;
 
 	spin_lock(&journal->j_list_lock);
-	if (jh->b_transaction != 0 && jh->b_cp_transaction == 0) {
+	if (jh->b_transaction != NULL && jh->b_cp_transaction == NULL) {
 		if (jh->b_jlist == BJ_SyncData || jh->b_jlist == BJ_Locked) {
 			/* A written-back ordered data buffer */
 			JBUFFER_TRACE(jh, "release data");
@@ -1603,7 +1603,7 @@
 			journal_remove_journal_head(bh);
 			__brelse(bh);
 		}
-	} else if (jh->b_cp_transaction != 0 && jh->b_transaction == 0) {
+	} else if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
 		/* written-back checkpointed metadata buffer */
 		if (jh->b_jlist == BJ_None) {
 			JBUFFER_TRACE(jh, "remove from checkpoint list");
@@ -1963,7 +1963,7 @@
 
 	J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
 	J_ASSERT_JH(jh, jh->b_transaction == transaction ||
-				jh->b_transaction == 0);
+				jh->b_transaction == NULL);
 
 	if (jh->b_transaction && jh->b_jlist == jlist)
 		return;