i965: Rename brw_disasm to brw_disassemble_inst.

i965: Rename brw_disasm to brw_disassemble_inst.

Fixes build error introduced with commit
4b04152db055babb8b06929a0c9ebea5c7f4fb92.

  CC       test_eu_compact.o
test_eu_compact.c: In function ‘test_compact_instruction’:
test_eu_compact.c:54:3: error: implicit declaration of function ‘brw_disasm’ [-Werror=implicit-function-declaration]
   brw_disasm(stderr, &src, brw->gen, false);
   ^

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78888
Signed-off-by: Vinson Lee <vlee@freedesktop.org>