Remove del_curterm workaround on *BSD.

FreeBSD PR was https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=108117
OpenBSD PR was 5447.

Both have been fixed for years.

This reverts commit c55cbd3f2f003ea6e36727f8b985e880d6aded85, among
others.

configure.ac

@@ -748,25 +748,6 @@ else
   AC_MSG_RESULT(no)
 fi
 
-# Check if del_curterm is broken - in that case we redefine
-# del_curterm as a no-op, to avoid a double-free
-
-AC_MSG_CHECKING([If del_curterm is broken])
-case $target_os in
-  *bsd*)
-    AC_MSG_RESULT(yes)
-    AC_DEFINE(
-      [HAVE_BROKEN_DEL_CURTERM],
-      [1],
-      [del_curterm is broken, redefine it to a no-op to avoid a double-free bug]
-    )
-    ;;
-  *)
-    AC_MSG_RESULT(no)
-    ;;
-esac
-
-
 # Tell the world what we know
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT

fallback.h

@@ -348,15 +348,6 @@ size_t wcslcpy(wchar_t *dst, const wchar_t *src, size_t siz);
 
 #endif
 
-/**
-   BSD del_curterm seems to do a double-free. We redefine it as a no-op
-*/
-#ifdef HAVE_BROKEN_DEL_CURTERM
-#define fish_del_curterm(X) OK
-#else
-#define fish_del_curterm(X) del_curterm(X)
-#endif
-
 #ifndef HAVE_LRAND48_R
 
 /**

input.cpp

@@ -528,7 +528,7 @@ void input_destroy()
 
     input_common_destroy();
 
-    if (fish_del_curterm(cur_term) == ERR)
+    if (del_curterm(cur_term) == ERR)
     {
         debug(0, _(L"Error while closing terminfo"));
     }