bt: check struct sizes

See http://permalink.gmane.org/gmane.linux.bluez.kernel/36505.  For historical
reasons these do not use sizeof, and Coverity caught a mistake in
EVT_ENCRYPT_CHANGE_SIZE.

In addition:

- remove status from create_conn_cancel_cp; the "status" field is only
in rp structs.  Note that this means that the OCF_CREATE_CONN_CANCEL
could never have worked (it would have failed the LENGTH_CHECK), but
I am keeping it anyway.

- OCF_READ_LINK_QUALITY similarly could never have worked, but I am
fixing read_link_quality_cp anyway.

- fix inquiry_info which is shorter by one: the kernel has a struct that
is 14 byte long, but not counting the initial num_responses byte which
the kernel parses separately;

- remove extended_inquiry_info altogether, since it's not used and unlike
the other inquiry structs does not have the initial num_responses byte.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
