RDMA/nes: Use proper format and cast to print dma_addr_t

On some platforms, eg sparc64, dma_addr_t is not the same size as a
pointer, so printing dma_addr_t values by casting to void * and using
a %p format generates warnings.  Fix this by casting to unsigned long
and using %lx instead.  This fixes the warnings:

    drivers/infiniband/hw/nes/nes_verbs.c: In function 'nes_setup_virt_qp':
    drivers/infiniband/hw/nes/nes_verbs.c:1047: warning: cast to pointer from integer of different size
    drivers/infiniband/hw/nes/nes_verbs.c:1078: warning: cast to pointer from integer of different size
    drivers/infiniband/hw/nes/nes_verbs.c:1078: warning: cast to pointer from integer of different size
    drivers/infiniband/hw/nes/nes_verbs.c: In function 'nes_reg_user_mr':
    drivers/infiniband/hw/nes/nes_verbs.c:2657: warning: cast to pointer from integer of different size

Reported by Andrew Morton <akpm@linux-foundation.org>.

Signed-off-by: Roland Dreier <rolandd@cisco.com>