intel/tools: avoid 'unused variable' warnings

intel/tools: avoid 'unused variable' warnings

1. tools/aub_read.c:271:31: warning: unused variable ‘end’
    const uint32_t *p = data, *end = data + data_len, *next;

2. tools/aub_mem.c:292:13: warning: unused variable ‘res’
       void *res = mmap((uint8_t *)bo.map + map_offset, 4096, PROT_READ,
   tools/aub_mem.c:357:13: warning: unused variable ‘res’
       void *res = mmap((uint8_t *)bo.map + (page - bo.addr), 4096, PROT_READ,

v2: The i965_disasm.c changes was moved into a separate patch
    The 'end' variable declared separately with MAYBE_UNUSED
    to avoid effect of it to other variables.
       ( Eric Engestrom <eric.engestrom@intel.com> )

Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>