Revert "RDMA/nes: Fix compilation error when nes_debug is enabled"

This reverts commit bca1935c, which removes variables
nes_tcp_state_str and nes_iwarp_state_str, assuming that they aren't
defined.  However, they are defined within a #ifdef NES_DEBUG statement,
which if enabled causes "defined but not used" compiler warning, when
the variables are removed.

Signed-off-by: Tatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Roland Dreier <roland@purestorage.com>