MBUF - Do not limit an objcache common pool to 10 magazines.
* An objcache's common magazine pool was limited to 10 in order to return
memory to the system sooner rather then later.
This created a situation with the mbuf allocator where high-rate
mbuf producers (GigE, 10GigE) would sometimes not be able to allocate
a large enough batch of mbufs and drop packets. 10 magazines x 64 is
only 640 mbufs.
* Increase the limit from 10 to 1000.
Tested-with: 10GigE setup from Aggelos Economopoulos <aoiko@cc.ece.ntua.gr>