tools lib symbol: Rename kallsyms2elf_type to kallsyms2elf_binding

tools lib symbol: Rename kallsyms2elf_type to kallsyms2elf_binding

It is about binding, not type, we have just a letter in kallsyms that
should map both for the ELF type (STT_FUNC, etc) and to the ELF
symbol binding (STB_WEAK, STB_GLOBAL, etc), so rename it now before
introducing kallsyms2_elf_type()

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-uu5vj343ms1q2wm55690on6v@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>