lantiq: replace backticks by $(...) and remove useless echo

This replaces deprecated backticks by more versatile $(...) syntax.

Signed-off-by: Adrian Schmutzler <[email protected]>
[decapitalized patch subject at submitter's request]
Signed-off-by: Christian Lamparter <[email protected]>

target/linux/lantiq/base-files/etc/hotplug.d/dsl/pppoa.sh

@@ -8,7 +8,7 @@
 include /lib/network
 scan_interfaces
 
-interfaces=`ubus list network.interface.\* | cut -d"." -f3`
+interfaces=$(ubus list network.interface.\* | cut -d"." -f3)
 for ifc in $interfaces; do
 
 	json_load "$(ifstatus $ifc)"

target/linux/lantiq/base-files/lib/functions/lantiq_dsl.sh

@@ -290,8 +290,8 @@ xtse() {
 		annex_s="$annex_s M,"
 	fi
 
-	annex_s=`echo ${annex_s:1}`
-	annex_s=`echo ${annex_s%?}`
+	annex_s=${annex_s:1}
+	annex_s=${annex_s%?}
 
 	# Evaluate Line Mode (according to G.997.1, 7.3.1.1.1)
 
@@ -346,8 +346,8 @@ xtse() {
 		line_mode_s="$line_mode_s G.993.1 (VDSL),"
 	fi
 
-	line_mode_s=`echo ${line_mode_s:1}`
-	line_mode_s=`echo ${line_mode_s%?}`
+	line_mode_s=${line_mode_s:1}
+	line_mode_s=${line_mode_s%?}
 
 	xtse_s="${xtse1}, ${xtse2}, ${xtse3}, ${xtse4}, ${xtse5}, ${xtse6}, ${xtse7}, ${xtse8}"