package/screen: fix usage with readonly rootfs

Buildroot commit 4769724ee2 bumped the
package from 4.9.1 to 5.0.0 which includes a major rewrite of the
configure script
https://cgit.git.savannah.gnu.org/cgit/screen.git/log/src/configure.ac?h=v.4.9.1
https://cgit.git.savannah.gnu.org/cgit/screen.git/log/src/configure.ac?h=v.5.0.0

By default, screen puts the socket directory in $HOME/.screen, which
is not writable when the rootfs is readonly:

 # screen
 Cannot access /root/.screen: No such file or directory

The --enable-socket-dir option added in upstream commit
https://cgit.git.savannah.gnu.org/cgit/screen.git/commit/?id=78a961188f7da528c7cefcc63e07f35f04e69a93
allows to configure this, and actually its default value of
/run/screen is sensible, so we fix the problem by simply passing
--enable-socket-dir, and rely on its default setting.

Fixes:

  https://gitlab.com/buildroot.org/buildroot/-/issues/123

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/screen/screen.mk

@@ -13,7 +13,7 @@ SCREEN_SELINUX_MODULES = screen
 SCREEN_DEPENDENCIES = ncurses
 SCREEN_AUTORECONF = YES
 SCREEN_CONF_ENV = CFLAGS="$(TARGET_CFLAGS)"
-SCREEN_CONF_OPTS = --enable-colors256
+SCREEN_CONF_OPTS = --enable-colors256 --enable-socket-dir
 SCREEN_INSTALL_TARGET_OPTS = DESTDIR=$(TARGET_DIR) SCREEN=screen install_bin
 
 ifeq ($(BR2_PACKAGE_LIBXCRYPT),y)