See if we can get rid of the "lib" in front of "wsutil" on Windows.

"libXXX" is a UN*X convention; see whether we can do without it on
Windows.

Change-Id: I03a377ed5121a8dff7a53203b34e441abffcbb85
Reviewed-on: https://code.wireshark.org/review/2968
Reviewed-by: Guy Harris <guy@alum.mit.edu>