intel/batch-decoder: fix uninitialized values warnings

intel/batch-decoder: fix uninitialized values warnings

Code assumes that all the necessary fields will exist, but compiler
doesn't know about this. Provide zero as default values, like in other
decoding functions.

Fixes warnings

../../src/intel/common/gen_batch_decoder.c: In function ‘handle_media_interface_descriptor_load’:
../../src/intel/common/gen_batch_decoder.c:347:7: warning: ‘binding_entry_count’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       dump_binding_table(ctx, binding_table_offset, binding_entry_count);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../src/intel/common/gen_batch_decoder.c:347:7: warning: ‘binding_table_offset’ may be used uninitialized in this function [-Wmaybe-uninitialized]

../../src/intel/common/gen_batch_decoder.c:346:7: warning: ‘sampler_count’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       dump_samplers(ctx, sampler_offset, sampler_count);
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../src/intel/common/gen_batch_decoder.c:346:7: warning: ‘sampler_offset’ may be used uninitialized in this function [-Wmaybe-uninitialized]

../../src/intel/common/gen_batch_decoder.c:343:7: warning: ‘ksp’ may be used uninitialized in this function [-Wmaybe-uninitialized]
       ctx_disassemble_program(ctx, ksp, "compute shader");
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

../../src/intel/common/gen_batch_decoder.c: In function ‘decode_dynamic_state_pointers’:
../../src/intel/common/gen_batch_decoder.c:663:54: warning: ‘state_offset’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    const uint32_t *state_map = ctx->dynamic_base.map + state_offset;
                                ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~

../../src/intel/common/gen_batch_decoder.c: In function ‘gen_print_batch’:
../../src/intel/common/gen_batch_decoder.c:856:13: warning: ‘next_batch.map’ may be used uninitialized in this function [-Wmaybe-uninitialized]
          if (next_batch.map == NULL) {
             ^
../../src/intel/common/gen_batch_decoder.c:860:13: warning: ‘next_batch.addr’ may be used uninitialized in this function [-Wmaybe-uninitialized]
             gen_print_batch(ctx, next_batch.map, next_batch.size,
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                             next_batch.addr);
                             ~~~~~~~~~~~~~~~~

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>