fix a build error, /usr/bin/ld: cannot find -ledlib

[moold]

I can't build edlib-rs successfully due to this error:

note: /usr/bin/ld: cannot find -ledlib
  collect2: error: ld returned 1 exit status

After checking the edlib-c build directory:

bindings.rs
build
include
lib64
wrapper.h

there is no lib directory (I don't know why), but there is a directory lib64, so I added this line println!("{}64",libdir); to build.rs and it fixed this error.

[jean-pierreBoth]

I suppose you have a configuration of cmake that make it create lib instead of lib64

[moold]

In fact, I didn't change any code from edlib-rs.