Bluetooth: qca: add missing firmware sanity checks

Bluetooth: qca: add missing firmware sanity checks

commit 2e4edfa1e2bd821a317e7d006517dcf2f3fac68d upstream.

Add the missing sanity checks when parsing the firmware files before
downloading them to avoid accessing and corrupting memory beyond the
vmalloced buffer.

Fixes: 83e81961ff7e ("Bluetooth: btqca: Introduce generic QCA ROME support")
Cc: stable@vger.kernel.org	# 4.10
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>