Added NCCL error checking to tests.

Also cleaned up makefile so that tests and lib are not built unnecessarily.

Change-Id: Ia0c596cc2213628de2f066be97615c09bb1bb262
Reviewed-on: http://git-master/r/999627
Reviewed-by: Przemek Tredak <ptredak@nvidia.com>
Tested-by: Przemek Tredak <ptredak@nvidia.com>

test/include/test_utilities.h

@@ -32,14 +32,23 @@
 
 #include <curand.h>
 
-#define CUDACHECK(cmd) do {                              \
-    cudaError_t e = cmd;                                 \
-    if( e != cudaSuccess ) {                             \
-        printf("Cuda failure %s:%d '%s'\n",              \
-               __FILE__,__LINE__,cudaGetErrorString(e)); \
-        exit(EXIT_FAILURE);                              \
-    }                                                    \
-} while(false)
+#define CUDACHECK(cmd) do {                         \
+  cudaError_t e = cmd;                              \
+  if( e != cudaSuccess ) {                          \
+    printf("Cuda failure %s:%d '%s'\n",             \
+        __FILE__,__LINE__,cudaGetErrorString(e));   \
+    exit(EXIT_FAILURE);                             \
+  }                                                 \
+} while(0)
+
+#define NCCLCHECK(cmd) do {                         \
+  ncclResult_t r = cmd;                             \
+  if (r!= ncclSuccess) {                            \
+    printf("NCCL failure %s:%d '%s'\n",             \
+        __FILE__,__LINE__,ncclGetErrorString(r));   \
+    exit(EXIT_FAILURE);                             \
+  }                                                 \
+} while(0)
 
 template<typename T>
 void Randomize(T* const dest, const int N, const int randomSeed);