firmware: tegra: Fix error check return value of debugfs_create_file()

If an error occurs, debugfs_create_file() will return ERR_PTR(-ERROR),
so use IS_ERR() to check it.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/firmware/tegra/bpmp-debugfs.c

@@ -474,7 +474,7 @@ static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
 			mode |= attrs & DEBUGFS_S_IWUSR ? 0200 : 0;
 			dentry = debugfs_create_file(name, mode, parent, bpmp,
 						     &bpmp_debug_fops);
-			if (!dentry) {
+			if (IS_ERR(dentry)) {
 				err = -ENOMEM;
 				goto out;
 			}
@@ -725,7 +725,7 @@ static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
 
 		if (t & DEBUGFS_S_ISDIR) {
 			dentry = debugfs_create_dir(name, parent);
-			if (!dentry)
+			if (IS_ERR(dentry))
 				return -ENOMEM;
 			err = bpmp_populate_dir(bpmp, seqbuf, dentry, depth+1);
 			if (err < 0)
@@ -738,7 +738,7 @@ static int bpmp_populate_dir(struct tegra_bpmp *bpmp, struct seqbuf *seqbuf,
 			dentry = debugfs_create_file(name, mode,
 						     parent, bpmp,
 						     &debugfs_fops);
-			if (!dentry)
+			if (IS_ERR(dentry))
 				return -ENOMEM;
 		}
 	}
@@ -788,11 +788,11 @@ int tegra_bpmp_init_debugfs(struct tegra_bpmp *bpmp)
 		return 0;
 
 	root = debugfs_create_dir("bpmp", NULL);
-	if (!root)
+	if (IS_ERR(root))
 		return -ENOMEM;
 
 	bpmp->debugfs_mirror = debugfs_create_dir("debug", root);
-	if (!bpmp->debugfs_mirror) {
+	if (IS_ERR(bpmp->debugfs_mirror)) {
 		err = -ENOMEM;
 		goto out;
 	}