macintosh/smu: Fix warning comparing pointer to 0

Fix the following coccicheck warning:
  ./drivers/macintosh/smu.c:1089: 11-12:
   WARNING comparing pointer to 0, suggest !E
  ./drivers/macintosh/smu.c:1256:11-12:
  WARNING comparing pointer to 0
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Jing Yangyang <jing.yangyang@zte.com.cn>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210825061838.69746-1-deng.changcheng@zte.com.cn

drivers/macintosh/smu.c

@@ -1087,7 +1087,7 @@ static int smu_open(struct inode *inode, struct file *file)
 	unsigned long flags;
 
 	pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
-	if (pp == 0)
+	if (!pp)
 		return -ENOMEM;
 	spin_lock_init(&pp->lock);
 	pp->mode = smu_file_commands;
@@ -1254,7 +1254,7 @@ static __poll_t smu_fpoll(struct file *file, poll_table *wait)
 	__poll_t mask = 0;
 	unsigned long flags;
 
-	if (pp == 0)
+	if (!pp)
 		return 0;
 
 	if (pp->mode == smu_file_commands) {
@@ -1277,7 +1277,7 @@ static int smu_release(struct inode *inode, struct file *file)
 	unsigned long flags;
 	unsigned int busy;
 
-	if (pp == 0)
+	if (!pp)
 		return 0;
 
 	file->private_data = NULL;