Bluetooth: L2CAP: Fix responding with wrong PDU type

stable inclusion
from stable-v5.10.177
commit fce0e47e9ec5afa6123ca403bf2112dae59a9b84
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I88YNP

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fce0e47e9ec5afa6123ca403bf2112dae59a9b84



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[ Upstream commit 9aa9d947 ]

L2CAP_ECRED_CONN_REQ shall be responded with L2CAP_ECRED_CONN_RSP not
L2CAP_LE_CONN_RSP:

L2CAP LE EATT Server - Reject - run
  Listening for connections
  New client connection with handle 0x002a
  Sending L2CAP Request from client
  Client received response code 0x15
  Unexpected L2CAP response code (expected 0x18)
L2CAP LE EATT Server - Reject - test failed

> ACL Data RX: Handle 42 flags 0x02 dlen 26
      LE L2CAP: Enhanced Credit Connection Request (0x17) ident 1 len 18
        PSM: 39 (0x0027)
        MTU: 64
        MPS: 64
        Credits: 5
        Source CID: 65
        Source CID: 66
        Source CID: 67
        Source CID: 68
        Source CID: 69
< ACL Data TX: Handle 42 flags 0x00 dlen 16
      LE L2CAP: LE Connection Response (0x15) ident 1 len 8
        invalid size
        00 00 00 00 00 00 06 00

L2CAP LE EATT Server - Reject - run
  Listening for connections
  New client connection with handle 0x002a
  Sending L2CAP Request from client
  Client received response code 0x18
L2CAP LE EATT Server - Reject - test passed

Fixes: 15f02b91 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>
(cherry picked from commit 55e3c232)