octeontx2-af: Fix uninitialized variables in rvu_switch

Get the number of VFs of a PF correctly by calling
rvu_get_pf_numvfs in rvu_switch_disable function.
Also hwvf is not required hence remove it.

Fixes: 23109f8d ("octeontx2-af: Introduce internal packet switching")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>