usb: usbtmc: add ioctl USBTMC_IOCTL_MSG_IN_ATTR

usb: usbtmc: add ioctl USBTMC_IOCTL_MSG_IN_ATTR

add ioctl USBTMC_IOCTL_MSG_IN_ATTR that returns the specific
bmTransferAttributes field of the last DEV_DEP_MSG_IN Bulk-IN
header. This header is received by the read() function. The
meaning of the (u8) bitmap bmTransferAttributes is:

Bit 0 = EOM flag is set when the last transfer of a USBTMC
message is received.

Bit 1 = is set when the last byte is a termchar (e.g. '\n').
Note that this bit is always zero when the device does not support
the termchar feature or when termchar detection is not enabled
(see ioctl USBTMC_IOCTL_CONFIG_TERMCHAR).

Signed-off-by: Guido Kiener <guido.kiener@rohde-schwarz.com>
Reviewed-by: Steve Bayless <steve_bayless@keysight.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>