[openwrt/openwrt] dropbear: init: replace backticks with $()

[LEDE Commits]

adrian pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/69ca308673337b2759d5b188c8d5a4bc73405cb5

commit 69ca308673337b2759d5b188c8d5a4bc73405cb5
Author: Rui Salvaterra <rsalvaterra at gmail.com>
AuthorDate: Tue Jun 30 17:22:10 2020 +0100

    dropbear: init: replace backticks with $()
    
    This replaces deprecated backticks by more versatile $(...) syntax.
    
    Signed-off-by: Rui Salvaterra <rsalvaterra at gmail.com>
    [add commit description]
    Signed-off-by: Adrian Schmutzler <freifunk at adrianschmutzler.de>
---
 package/network/services/dropbear/files/dropbear.init | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/package/network/services/dropbear/files/dropbear.init b/package/network/services/dropbear/files/dropbear.init
index daf111fadb..ab8e908d8c 100755
--- a/package/network/services/dropbear/files/dropbear.init
+++ b/package/network/services/dropbear/files/dropbear.init
@@ -238,7 +238,7 @@ killclients()
 	while [ "${pid}" -ne 0 ]
 	 do
 		# get parent process id
-		pid=`cut -d ' ' -f 4 "/proc/${pid}/stat"`
+		pid=$(cut -d ' ' -f 4 "/proc/${pid}/stat")
 		[ "${pid}" -eq 0 ] && break
 
 		# check if client connection
@@ -249,14 +249,14 @@ killclients()
 	done
 
 	# get all server pids that should be ignored
-	for server in `cat /var/run/${NAME}.*.pid`
+	for server in $(cat /var/run/${NAME}.*.pid)
 	 do
 		append ignore "${server}"
 	done
 
 	# get all running pids and kill client connections
 	local skip
-	for pid in `pidof "${NAME}"`
+	for pid in $(pidof "${NAME}")
 	 do
 		# check if correct program, otherwise process next pid
 		grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" || {