svcrdma: Remove the SVCRDMA_DEBUG macro

Clean up: Commit d21b05f1 ("rdma: SVCRMDA Header File")
introduced the SVCRDMA_DEBUG macro, but it doesn't seem to have been
used.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

include/linux/sunrpc/svc_rdma.h

@@ -48,7 +48,6 @@
 #include <linux/sunrpc/rpc_rdma.h>
 #include <rdma/ib_verbs.h>
 #include <rdma/rdma_cm.h>
-#define SVCRDMA_DEBUG
 
 /* Default and maximum inline threshold sizes */
 enum {