names, metadata: reduce scope of some vars
namespace: catch return var of register_chrdev() in signed int
kdbus_msg_scan_items(): simplify item size logic
namespace: pre-calculate payload_size to simplify code
some trivial style-related fixups
headers: more trivial style complaints
remove unneeded include headers
connection: use kcalloc when allocating arrays
remove kdbus_msg_dump
avoid block in case statements unless necessary
pool: use {} in all conditional branches if used in one of them
handle: plug memory leak in case copy_to_user() fails
add KDBUS_CMD_BYEBYE
document KDBUS_CMD_BYEBYE
test-kdbus: add test for BYEBYE
include uaccess.h where needed
include linux/uaccess.h from all files that use copy_{from,to}_user
handle: clean up error path

no functional change.
kdbus.h cosmetics
make kdbus_notify_name_change consist of two kdbus_notify_id_change