Revert "libertas: Read buffer overflow"

This reverts commit 57921c312e8cef72ba35a4cfe870b376da0b1b87.

On request from John Linville:

	It has been shown to create a new problem.  There is work
	towards a solution to that one, but it isn't a simple
	clean-up.

Signed-off-by: David S. Miller <davem@davemloft.net>