net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc

net: dsa: bcm_sf2: fix buffer overflow doing set_rxnfc

The "fs->location" is a u32 that comes from the user in ethtool_set_rxnfc().
We can't pass unclamped values to test_bit() or it results in an out of
bounds access beyond the end of the bitmap.

Fixes: 7318166cacad ("net: dsa: bcm_sf2: Add support for ethtool::rxnfc")
Signed-off-by: Dan Carpenter <[email protected]>
Signed-off-by: David S. Miller <[email protected]>