LEAdvertisingReportEP.Unmarshal panics for bad length packets

[thomasf]

This has paniced for me a few times, seems like something might be sending bad data (?).

That function could probably benefit from some additional length checks in general if it isn't done somewhere else.

panic(0x5a0b08, 0x10d0a018)
    /home/thomasf/.opt/go/src/runtime/panic.go:481 +0x330
.../vendor/github.com/currantlabs/gatt/linux/evt.(*LEAdvertisingReportEP).Unmarshal(0x12416f80, 0x1312500e, 0x1, 0xff2, 0x0, 0x0)
    .../vendor/github.com/currantlabs/gatt/linux/evt/evt.go:327 +0xb5c
.../vendor/github.com/currantlabs/gatt/linux.(*HCI).handleAdvertisement(0x114a4050, 0x13125003, 0xc, 0xffd)
    .../vendor/github.com/currantlabs/gatt/linux/hci.go:259 +0x78
created by .../vendor/github.com/currantlabs/gatt/linux.(*HCI).handleLEMeta
    .../vendor/github.com/currantlabs/gatt/linux/hci.go:371 +0xc4