Fix errors from previous commit

ompi/mpiext/cuda/c/mpiext_cuda.c

@@ -27,5 +27,5 @@
    support.  We may expand on this API to return more features in the future. */
 int MPIX_Query_cuda_support(void)
 {
-    return OMPI_SUCCESS;
+    return OPAL_SUCCESS;
 }

ompi/mpiext/cuda/c/mpiext_cuda_c.h

@@ -13,4 +13,4 @@
  */
 
 #define MPIX_CUDA_AWARE_SUPPORT 1
-OMPI_DECLSPEC int MPIx_CUDA_SUPPORT(void);
+OMPI_DECLSPEC int MPIX_Query_cuda_support(void);