staging: unisys: refactor DIAG_CHANNEL_EVENT

Get rid of the typedef on DIAG_CHANNEL_EVENT, and use struct diag_channel_event
instead. Update comments and fix CamelCase member names:

EventId => event_id
Severity => severity
ModuleName => module_name
LineNumber => line_number
Timestamp => timestamp
PartitionNumber => partition_number
VirtualProcessorNumber => vcpu_number
LogicalProcessorNumber => lcpu_number
ComponentType => component_type
Subsystem => subsystem
Reserved0 => reserved0
BlockNumber => block_no
BlockNumberHigh => block_no_high
EventNumber => event_no
EventNumberHigh => event_no_high
Reserved => reserved
AdditionalInfo => additional_info

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>