memif: fix the maxmimum number of txqs
Type: fix
With multi-txq in VPP, user should be able to create
more txqs than vpp threads. MEMIF_MAX_M2S_RING should
be defined to 256 instead of number of vpp threads.
#define MEMIF_DEFAULT_TX_QUEUES 1
#define MEMIF_DEFAULT_BUFFER_SIZE 2048
-#define MEMIF_MAX_M2S_RING (vlib_get_n_threads ())
+#define MEMIF_MAX_M2S_RING 256
#define MEMIF_MAX_S2M_RING 256
#define MEMIF_MAX_REGION 256
#define MEMIF_MAX_LOG2_RING_SIZE 14
