[build] Fix the check for editline in readline macro.
[build] Fix the check for editline in readline macro.

sureshsundriyal/lnav,tstack/lnav,acleasby/lnav,acleasby/lnav,acleasby/lnav,tstack/lnav,tstack/lnav,sureshsundriyal/lnav,sureshsundriyal/lnav,tstack/lnav,acleasby/lnav,sureshsundriyal/lnav,acleasby/lnav