Remove redundant dump_opt_t.display_filter_params field

It was only ever set alongside display_dcpl in the same -p branch and
never read anywhere except to copy it into ctx.show_filter_params, so it
carried no information display_dcpl didn't already have. Source
show_filter_params from display_dcpl directly. Also fixes the duplicate
dump_opt_t definition in h5dump_extern.h to match, and its now-stale
trailing initializer value in h5dump.h.

tools/src/h5dump/h5dump.c

@@ -785,10 +785,6 @@ parse_start:
                 break;
             case 'p':
                 dump_opts.display_dcpl = true;
-                /* RFC-HDFG-2026-001 §9: -p also prints PARAMS_STRING in the
-                 * FILTERS block, matching the existing per-filter PARAMS{}
-                 * output for user-defined filters. */
-                dump_opts.display_filter_params = true;
                 break;
             case 'y':
                 dump_opts.display_ai = false;

tools/src/h5dump/h5dump.h

@@ -283,10 +283,9 @@ typedef struct {
     int include_attrs;          /* Display attributes */
     int display_vds_first;      /* vds display to all by default */
     int vds_gap_size;           /* vds skip missing files default is none */
-    int display_filter_params;  /* emit PARAMS_STRING in FILTERS block */
 } dump_opt_t;
 dump_opt_t dump_opts = {true, false, true,  true,  false, false, false, false, false,
-                        true, false, false, false, false, true,  false, 0,     false};
+                        true, false, false, false, false, true,  false, 0};
 
 #define PACKED_BITS_MAX      8                       /* Maximum number of packed-bits to display */
 #define PACKED_BITS_SIZE_MAX (8 * sizeof(long long)) /* Maximum bits size of integer types of packed-bits */

tools/src/h5dump/h5dump_ddl.c

@@ -958,7 +958,7 @@ dump_dataset(hid_t did, const char *name, struct subset_t *sset)
     memset(&ctx, 0, sizeof(ctx));
     ctx.indent_level       = dump_indent / COL;
     ctx.cur_column         = dump_indent;
-    ctx.show_filter_params = dump_opts.display_filter_params;
+    ctx.show_filter_params = dump_opts.display_dcpl;
 
     string_dataformat = *outputformat;
 

tools/src/h5dump/h5dump_extern.h

@@ -78,7 +78,6 @@ typedef struct {
     int include_attrs;          /* Display attributes */
     int display_vds_first;      /* vds display to all by default */
     int vds_gap_size;           /* vds skip missing files default is none */
-    int display_filter_params;  /* emit PARAMS_STRING in FILTERS block */
 } dump_opt_t;
 extern dump_opt_t dump_opts;