Add create_fun_list.rb to create a list of functions in dm-thin things.

Add functions in list to set_ftrace_filter makes a desired trace

Like this:

 7)               |  thin_map() {
 7)               |    thin_bio_map.isra.40() {
 7)   0.073 us    |      __check_holder();
 7)               |      __add_holder() {
 7)   0.025 us    |        __find_holder();
 7)   0.299 us    |      }
 7)   0.036 us    |      dm_bm_validate_buffer.isra.4();
 7)   0.027 us    |      __check_holder();
 7)               |      __add_holder() {
 7)   0.023 us    |        __find_holder();
 7)   0.276 us    |      }
 7)   0.023 us    |      dm_bm_validate_buffer.isra.4();
 7)               |      bl_up_read() {
 7)   0.025 us    |        __find_holder();
 7)   0.426 us    |      }
 7)               |      bl_up_read() {
 7)   0.019 us    |        __find_holder();
 7)   0.386 us    |      }
 7)               |      thin_defer_bio() {
 7) + 17.115 us   |        wake_worker();
 7) + 17.737 us   |      }
 7) + 26.629 us   |    }
 7) + 27.060 us   |  }

Signed-off-by: Akira Hayakawa <ruby.wktk@gmail.com>