ubifs: Massage assert in ubifs_xattr_set() wrt. init_xattrs

The inode is not locked in init_xattrs when creating a new inode.

Without this patch, there will occurs assert when booting or creating
a new file, if the kernel config CONFIG_SECURITY_SMACK is enabled.

Log likes:

UBIFS assert failed in ubifs_xattr_set at 298 (pid 1156)
CPU: 1 PID: 1156 Comm: ldconfig Tainted: G S 4.12.0-rc1-207440-g1e70b02 #2
Hardware name: MediaTek MT2712 evaluation board (DT)
Call trace:
[<ffff000008088538>] dump_backtrace+0x0/0x238
[<ffff000008088834>] show_stack+0x14/0x20
[<ffff0000083d98d4>] dump_stack+0x9c/0xc0
[<ffff00000835d524>] ubifs_xattr_set+0x374/0x5e0
[<ffff00000835d7ec>] init_xattrs+0x5c/0xb8
[<ffff000008385788>] security_inode_init_security+0x110/0x190
[<ffff00000835e058>] ubifs_init_security+0x30/0x68
[<ffff00000833ada0>] ubifs_mkdir+0x100/0x200
[<ffff00000820669c>] vfs_mkdir+0x11c/0x1b8
[<ffff00000820b73c>] SyS_mkdirat+0x74/0xd0
[<ffff000008082f8c>] __sys_trace_return+0x0/0x4

Signed-off-by: Xiaolei Li <xiaolei.li@mediatek.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
index 382ed42..114ba45 100644
--- a/fs/ubifs/crypto.c
+++ b/fs/ubifs/crypto.c
@@ -9,8 +9,13 @@ static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
 static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
 				   size_t len, void *fs_data)
 {
+	/*
+	 * Creating an encryption context is done unlocked since we
+	 * operate on a new inode which is not visible to other users
+	 * at this point. So, no need to check whether inode is locked.
+	 */
 	return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
-			       ctx, len, 0);
+			       ctx, len, 0, false);
 }
 
 static bool ubifs_crypt_empty_dir(struct inode *inode)