Remove ancient hack to work around a peculiarity of libcurses on HPUX.

Since we now use libtermcap in preference to libcurses, no need for hack
anymore.

src/makefiles/Makefile.hpux

-# HP-UX 10 has a select() in libcurses, so we need to get the libc version,
-# which we do by linking -lc before -lcurses.  (Unfortunately we can't
-# just not use libcurses.)  This also ensures that we get the POSIX signal
-# routines in libc, not the BSD-like ones in libBSD.
-LIBS := -lc $(LIBS)
-
-# On the other hand, if we don't have POSIX signals, we need to use the
-# libBSD signal routines.  (HPUX 9 and early HPUX 10 releases don't have
-# POSIX signals.)  Make sure libBSD comes before libc in that case.
+# If we don't have POSIX signals, we need to use the libBSD signal routines.
+# (HPUX 9 and early HPUX 10 releases don't have POSIX signals.)  Link in
+# libBSD only in that case.
 ifeq ($(HAVE_POSIX_SIGNALS), no)
    LIBS := -lBSD $(LIBS)
 endif