ugps: fix and improve init script

The ugps tool expects device path in last argument. If it's provided
before other options, they won't be processed at all.

Additionally, make it possible to use absolute path for gps character
device in related uci configuration.

Signed-off-by: Piotr Dymacz <pepe2k@gmail.com>

package/utils/ugps/Makefile

@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ugps
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE_URL=$(LEDE_GIT)/project/ugps.git
 PKG_SOURCE_PROTO:=git

package/utils/ugps/files/ugps.init

@@ -14,11 +14,15 @@ start_service() {
 	local tty="$(uci get gps.@gps[-1].tty)"
 	local atime="$(uci get gps.@gps[-1].adjust_time)"
 
-	[ -d "/sys/class/tty/$tty/" ] || return
+	[ -c "$tty" ] || {
+		tty="/dev/$tty"
+		[ -c "$tty" ] || return
+	}
 
 	procd_open_instance
-	procd_set_param command "$PROG" "/dev/$tty"
+	procd_set_param command "$PROG"
 	[ "$atime" -eq 0 ] || procd_append_param command "-a"
+	procd_append_param command "$tty"
 	procd_set_param respawn
 	procd_close_instance
 }