make: unifdef for other OSes (undefined)

*** 36,48 ****
  #include <sys/socket.h>
  #include <sys/stat.h>
  #include <sys/types.h>
  #include <sys/utsname.h>
  #include <rpc/rpc.h>            /* host2netname(), netname2host() */
- #ifdef linux
- #       include <unistd.h>      /* getdomainname() */
- #endif
  
  /*
   * Defined macros
   */
  
--- 36,45 ----
*** 196,212 ****
          local_host_wslen = wslen(local_host);
  
          // There is no getdomainname() function on Solaris.
          // And netname2host() function does not work on Linux.
          // So we have to use different APIs.
- #ifdef linux
-         if (getdomainname(mbs_buffer, MAXNETNAMELEN+1) == 0) {
-                 sprintf(mbs_buffer2, "%s.%s", local_host_mb, mbs_buffer);
- #else
          if (host2netname(mbs_buffer, NULL, NULL) &&
              netname2host(mbs_buffer, mbs_buffer2, MAXNETNAMELEN+1)) {
- #endif
                  MBSTOWCS(full_host, mbs_buffer2);
                  full_host_wslen = wslen(full_host);
          }
  
          for (ms = make_machines_list;
--- 193,204 ----