qlge: Use one path to (re)fill rx buffers.

Currently there are two paths for filling rx buffer queues. One is
used during initialization and the other during runtime.  This patch
removes ql_alloc_sbq_buffers() and ql_alloc_lbq_buffers() and replaces
them with a call to the runtime functions ql_update_lbq() and
ql_update_sbq().

Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>