NULL noise: fs/*, mm/*, kernel/*

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index e9c2fb0..53d86b4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2082,7 +2082,7 @@
 
 		kfree(pidarray);
 	} else {
-		ctr->buf = 0;
+		ctr->buf = NULL;
 		ctr->bufsz = 0;
 	}
 	file->private_data = ctr;
@@ -2614,7 +2614,7 @@
 
 static int cgroupstats_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, proc_cgroupstats_show, 0);
+	return single_open(file, proc_cgroupstats_show, NULL);
 }
 
 static struct file_operations proc_cgroupstats_operations = {
diff --git a/kernel/futex.c b/kernel/futex.c
index 87a6428..e43945e 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -281,7 +281,7 @@
  */
 static void get_futex_key_refs(union futex_key *key)
 {
-	if (key->both.ptr == 0)
+	if (key->both.ptr == NULL)
 		return;
 	switch (key->both.offset & (FUT_OFF_INODE|FUT_OFF_MMSHARED)) {
 		case FUT_OFF_INODE: