Compile warning from -Wstringop-overread

ncmpio_filetype.c: In function 'type_create_subarray64.constprop':
ncmpio_filetype.c:154:21: warning: 'MPI_Type_create_subarray' reading 4 bytes from a region of size 0 [-Wstringop-overread]
154 |         mpireturn = MPI_Type_create_subarray(ndims, sizes, subsizes, starts,
    |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
155 |                                              order, oldtype, newtype);
    |                                              ~~~~~~~~~~~~~~~~~~~~~~~~
ncmpio_filetype.c:154:21: note: referencing argument 3 of type 'const int *'
ncmpio_filetype.c:154:21: warning: 'MPI_Type_create_subarray' reading 4 bytes from a region of size 0 [-Wstringop-overread]
ncmpio_filetype.c:154:21: note: referencing argument 4 of type 'const int *'
In file included from ncmpio_filetype.c:18:
/opt/cray/pe/mpich/8.1.25/ofi/gnu/9.1/include/mpi.h:1362:5: note: in a call to function 'MPI_Type_create_subarray'
1362 | int MPI_Type_create_subarray(int ndims, const int array_of_sizes[],
     |     ^~~~~~~~~~~~~~~~~~~~~~~~

src/drivers/ncmpio/ncmpio_filetype.c

@@ -137,13 +137,10 @@ type_create_subarray64(int               ndims,
     }
 
     if (tag == 0) {
-        int gsizes[24], *sizes, *subsizes, *starts;
+        int *sizes, *subsizes, *starts;
         /* none of dimensions > 2^31-1, we can safely use
          * MPI_Type_create_subarray */
-        if (ndims <= 8) /* avoid malloc */
-            sizes = gsizes;
-        else
-            sizes = (int*) NCI_Malloc((size_t)ndims * 3 * SIZEOF_INT);
+        sizes = (int*) NCI_Malloc((size_t)ndims * 3 * SIZEOF_INT);
         subsizes = sizes    + ndims;
         starts   = subsizes + ndims;
         for (i=0; i<ndims; i++) {
@@ -156,7 +153,7 @@ type_create_subarray64(int               ndims,
         if (mpireturn != MPI_SUCCESS)
             err = ncmpii_error_mpi2nc(mpireturn, "MPI_Type_create_subarray");
 
-        if (ndims > 8) NCI_Free(sizes);
+        NCI_Free(sizes);
         return err;
     }