package/cvs: fix build without editor

Set default editor to /bin/vi to fix the following build failure when no
editor is found on host:

configure:40833: checking for vim
configure:40862: result: no
configure:40833: checking for vi
configure:40862: result: no
configure:40833: checking for emacs
configure:40862: result: no
configure:40833: checking for nano
configure:40862: result: no
configure:40833: checking for pico
configure:40862: result: no
configure:40833: checking for edit
configure:40862: result: no
configure:40874: error:
    Failed to find a text file editor.  CVS cannot be compiled
    without a default log message editor.  Searched for
    `vim vi emacs nano pico edit'.  Try `configure --with-editor'.

While at it, drop CVS_CONFIGURE_ARGS variable for simplicity

Fixes:
 - http://autobuild.buildroot.org/results/5b8a747698bc2e64eb1f001e87577e86e4cb8d14

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
(cherry picked from commit 1455d5241b288770aeea7f5ba6dcd1ea31966ba1)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/cvs/cvs.mk

@@ -18,18 +18,18 @@ CVS_CONF_ENV = \
 	ac_cv_func_working_mktime=yes \
 	cvs_cv_func_printf_ptr=yes
 
-CVS_CONFIGURE_ARGS = --disable-old-info-format-support
+CVS_CONF_OPTS = \
+	--disable-old-info-format-support \
+	--with-editor=/bin/vi
 ifeq ($(BR2_PACKAGE_CVS_SERVER),y)
-CVS_CONFIGURE_ARGS += --enable-server
+CVS_CONF_OPTS += --enable-server
 else
-CVS_CONFIGURE_ARGS += --disable-server
+CVS_CONF_OPTS += --disable-server
 endif
 ifeq ($(BR2_PACKAGE_ZLIB),y)
-CVS_CONFIGURE_ARGS += --with-external-zlib
+CVS_CONF_OPTS += --with-external-zlib
 endif
 
-CVS_CONF_OPTS = $(CVS_CONFIGURE_ARGS)
-
 define CVS_BZIP_UNPACK
 	$(BZCAT) $(@D)/cvs-$(CVS_VERSION).tar.bz2 | tar -C $(BUILD_DIR) $(TAR_OPTIONS) -
 	rm -f $(@D)/cvs-$(CVS_VERSION).tar.bz2