perf probe: Remove redundant dwarf functions

Since there are dwarf_bitsize, dwarf_bitoffset and dwarf_bytesize
defined in libdw, we don't need die_get_bit_size, die_get_bit_offset
and die_get_byte_size anymore.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072721.6528.2747.stgit@fedora15


Signed-off-by: Steven Rostedt <rostedt@goodmis.org>