ubifs: Fix memory leak bug in alloc_ubifs_info() error path

In ubifs_mount(), 'c' is allocated through kzalloc() in alloc_ubifs_info().
However, it is not deallocated in the following execution if
ubifs_fill_super() fails, leading to a memory leak bug. To fix this issue,
free 'c' before going to the 'out_deact' label.

Fixes: 1e51764 ("UBIFS: add new flash file system")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Richard Weinberger <richard@nod.at>

fs/ubifs/super.c

@@ -2256,8 +2256,10 @@ static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
 		}
 	} else {
 		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
-		if (err)
+		if (err) {
+			kfree(c);
 			goto out_deact;
+		}
 		/* We do not support atime */
 		sb->s_flags |= SB_ACTIVE;
 		if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))