syslog-ng: alternative for logread

When the syslog-ng installed it records all messages to /var/log/messages.
This makes the default OpenWrt's ubox /sbin/logread useless and return nothing.

The logread script was added to the syslog-ng as a shim.
It's based on `tail /var/log/messages` and repeats basic options that the ubox logread have.
The script is installed instead of the /sbin/logread and this is causes an error.

Instead install it to /usr/libexec/logread.sh and specify as an alternative /sbin/logread.

The ubox logread also needs to be made as alternative in /usr/libexec/logread-ubox.

So we need to give it a separate name.
The most simple and clear would be logread-shell or just logread.sh.

Suggested-by: Andreas Gnau <andreas.gnau@iopsys.eu>
Signed-off-by: Sergey Ponomarev <stokito@gmail.com>

admin/syslog-ng/Makefile

@@ -2,7 +2,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=syslog-ng
 PKG_VERSION:=4.7.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_MAINTAINER:=Josef Schlehofer <pepe.schlehofer@gmail.com>
 PKG_LICENSE:=LGPL-2.1-or-later GPL-2.0-or-later
@@ -35,6 +35,7 @@ define Package/syslog-ng
   TITLE:=A powerful syslog daemon
   URL:=https://www.syslog-ng.com/products/open-source-log-management/
   DEPENDS:=+libpcre2 +glib2 +libopenssl +libpthread +librt +libdbi +libjson-c +libcurl +libuuid +SYSLOGNG_LOGROTATE:logrotate +LIBCURL_ZLIB:zlib
+  ALTERNATIVES:=300:/sbin/logread:/usr/libexec/logread.sh
 endef
 
 define Package/syslog-ng/description
@@ -123,8 +124,8 @@ define Package/syslog-ng/install
 	$(INSTALL_DATA) ./files/syslog-ng.conf $(1)/etc
 	touch $(1)/etc/syslog-ng.d/.keep
 
-	$(INSTALL_DIR) $(1)/sbin
-	$(INSTALL_BIN) ./files/logread $(1)/sbin
+	$(INSTALL_DIR) $(1)/usr/libexec
+	$(INSTALL_BIN) ./files/logread.sh $(1)/usr/libexec/logread.sh
 
 	$(INSTALL_DIR) $(1)/usr/share/syslog-ng/include/
 	$(CP) -r ./files/scl $(1)/usr/share/syslog-ng/include/