9p: rdma: remove duplicated #include

Removed duplicated #include <rdma/ib_verbs.h> in
net/9p/trans_rdma.c.
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NEric Van Hensbergen <ericvh@gmail.com>

net/9p/trans_rdma.c

@@ -45,7 +45,6 @@
 #include <net/9p/transport.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
-#include <rdma/ib_verbs.h>
 
 #define P9_PORT			5640
 #define P9_RDMA_SQ_DEPTH	32