Bluetooth: controller: Fix a bug in ctrl and data management

Fix the control and data packet management implementation
discovered during conformance testing.

This fixes:
TP/SEC/MAS/BV-12 [Master Start Encryption: Overlapping
Procedure]
TP/SEC/MAS/BV-13 [Master Start Encryption: Overlapping
Procedure with LL_SLAVE_FEATURES_REQ]
conformance tests in LL.TS.5.0.0.

Signed-off-by: Vinayak Kariappa Chettimada <vich@nordicsemi.no>