scripts: Use $(..) instead of deprecated `..`
This fixes these warnings from shellcheck:
^-- SC2006: Use $(..) instead of deprecated `..`
Update also a comment using the same pattern.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
diff --git a/scripts/update-linux-headers.sh b/scripts/update-linux-headers.sh
index f7d62d9..08c4c4a 100755
--- a/scripts/update-linux-headers.sh
+++ b/scripts/update-linux-headers.sh
@@ -10,7 +10,7 @@
# This work is licensed under the terms of the GNU GPL version 2.
# See the COPYING file in the top-level directory.
-tmpdir=`mktemp -d`
+tmpdir=$(mktemp -d)
linux="$1"
output="$2"