staging: rtlwifi: use single_open and single_release properly

single_open() returns -ENOMEM when malloc failed, so the caller function
rtl_debugfs_open_rw() should not always return 0. In addition, when using
single_open(), we should use single_release() instead of seq_release() in
the file_operations structure to avoid a memory leak.
Signed-off-by: Tiezhu Yang <kernelpatch@126.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtlwifi/debug.c

@@ -95,7 +95,7 @@ static const struct file_operations file_ops_common = {
 	.open = dl_debug_open_common,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release,
+	.release = single_release,
 };
 
 static int rtl_debug_get_mac_page(struct seq_file *m, void *v)
@@ -485,18 +485,20 @@ static int rtl_debug_get_phydm_cmd(struct seq_file *m, void *v)
 
 static int rtl_debugfs_open_rw(struct inode *inode, struct file *filp)
 {
+	int ret = 0;
+
 	if (filp->f_mode & FMODE_READ)
-		single_open(filp, rtl_debug_get_common, inode->i_private);
+		ret = single_open(filp, rtl_debug_get_common, inode->i_private);
 	else
 		filp->private_data = inode->i_private;
 
-	return 0;
+	return ret;
 }
 
 static int rtl_debugfs_close_rw(struct inode *inode, struct file *filp)
 {
 	if (filp->f_mode == FMODE_READ)
-		seq_release(inode, filp);
+		single_release(inode, filp);
 
 	return 0;
 }