octeontx2-af: fix infinite loop in unmapping NPC counter

unmapping npc counter works in a way by traversing all mcam
entries to find which mcam rule is associated with counter.
But loop cursor variable 'entry' is not incremented before
checking next mcam entry which resulting in infinite loop.

This in turn hogs the kworker thread forever and no other
mbox message is processed by AF driver after that.
Fix this by updating entry value before checking next
mcam entry.

Fixes: a958dd59

 ("octeontx2-af: Map or unmap NPC MCAM entry and counter")
Signed-off-by: Hariprasad Kelam <hkelam@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>