Only pick one CUDA

In some cases the CUDA install directory contains two libcuda.so and
this breaks OMPI CUDA detection. Pick the first of these libraries seems
to be a good soltuion for all cases.

Signed-off-by: George Bosilca <[email protected]>
(cherry picked from commit c7e27b9)

Author: bosilca

config/opal_check_cuda.m4

@@ -60,8 +60,8 @@ AC_ARG_WITH([cuda-libdir],
                             [Search for CUDA libraries in DIR])],
             [],
             [AS_IF([test -d "$with_cuda"],
-             [with_cuda_libdir=$(dirname $(find -H $with_cuda -name libcuda.so 2> /dev/null) 2> /dev/null)],
-             [with_cuda_libdir=$(dirname $(find -H /usr/local/cuda -name libcuda.so 2> /dev/null) 2> /dev/null)])
+             [with_cuda_libdir=$(dirname $(find -H $with_cuda -name libcuda.so 2> /dev/null | head -n 1) 2> /dev/null)],
+             [with_cuda_libdir=$(dirname $(find -H /usr/local/cuda -name libcuda.so 2> /dev/null) 2> /dev/null | head -n 1)])
             ])
 
 # Note that CUDA support is off by default.  To turn it on, the user has to