Remove unused variables in test (#5808)

Fixes several warnings in Developer builds about variables declared past the start of the function

Author: jhendersonHDF

test/dsets.c

@@ -16893,21 +16893,17 @@ test_vds_shared_strings(hid_t fapl)
      */
     char file_name[64];
     char dset_name[64];
-    int  shared_file_count = 0;
-    int  shared_dset_count = 0;
 
     for (int i = 0; i < NUM_MAPPINGS_MANY; i++) {
         if (i % 10 == 0) {
             strcpy(file_name, "shared_file.h5");
-            shared_file_count++;
         }
         else {
             snprintf(file_name, sizeof(file_name), "file_%d.h5", i);
         }
 
         if (i % 5 == 0) {
             strcpy(dset_name, "/shared_dataset");
-            shared_dset_count++;
         }
         else {
             snprintf(dset_name, sizeof(dset_name), "/dataset_%d", i);