net/fm10k: fix internal switch initial status

net/fm10k: fix internal switch initial status

sm_down is a boolean in order to check if the internal switch of the
fm10k is up or down. This variable is configured though an interrupt by
fm10k_dev_interrupt_handler_pf.

If sm_down is uninitialized, we are not sure of its value at the first
bring up. For example, if FM10K_EICR_SWITCHREADY is raised, the PMD will
try to reconfigure the switch, but it does not make sense, as it's the
first startup.

The sm_down implementation has been introduced
commit 6c9f37245583 ("net/fm10k: support switch restart on PF").

Fixes: 6f22f2f67268 ("net/fm10k: redefine link status semantics")
Cc: stable@dpdk.org
Signed-off-by: Julien Meunier <julien.meunier@nokia.com>
Acked-by: Xiao Wang <xiao.w.wang@intel.com>