The original patch causes a crash with signed mounts when using
the SMB2.1 dialect

RIP: 0010:smb2_calc_signature+0x10e/0x460 [cifs]
Code: 46 30 00 00 00 00 49 c7 46 38 00 00 00 00 0f 85 3e 01 00 00 48 8b 83 a8 02 00 00 48 89 85 68 ff ff ff 49 8b b4 24 58 01 00 00 <48> 8b 38 ba 10 00 00 00 e8 55 0f 0c e0 41 89 c7 85 c0 0f 85 44 01
RSP: 0018:ffffb349422fb5c8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff98028765b800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff980200f2b100 RDI: 0000000000000000
RBP: ffffb349422fb680 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff980235e37800
R13: ffffb349422fb900 R14: ffff98027c160700 R15: ffff98028765b820
FS:  000074139b98f780(0000) GS:ffff98097b980000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000011cb78006 CR4: 00000000003726f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ? show_regs+0x6c/0x80
 ? __die+0x24/0x80
 ? page_fault_oops+0x175/0x5c0
 ? hrtimer_try_to_cancel.part.0+0x55/0xf0
 ? do_user_addr_fault+0x4b2/0x870
 ? exc_page_fault+0x85/0x1c0
 ? asm_exc_page_fault+0x27/0x30
 ? smb2_calc_signature+0x10e/0x460 [cifs]
 ? smb2_calc_signature+0xa7/0x460 [cifs]
 ? kmem_cache_alloc_noprof+0x101/0x300
 smb2_sign_rqst+0xa2/0xe0 [cifs]
 smb2_setup_request+0x12d/0x240 [cifs]
 compound_send_recv+0x304/0x1220 [cifs]
 cifs_send_recv+0x22/0x40 [cifs]
 SMB2_tcon+0x2d9/0x8c0 [cifs]
 cifs_get_smb_ses+0x910/0xef0 [cifs]
 ? cifs_get_smb_ses+0x910/0xef0 [cifs]
 cifs_mount_get_session+0x6a/0x250 [cifs]
Reported-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Suggested-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

This reverts commit 220d83b5.