devtools: fix bashism in mailmap check

When running check-git-log, it showed a "Bad substitution",
because of a bash syntax.

It is fixed by using sed to escape the open parenthesis.

Fixes: 6fd14c1 ("devtools: fix mailmap check for parentheses")
Cc: stable@dpdk.org

Signed-off-by: Raslan Darawsheh <rasland@nvidia.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>

devtools/check-git-log.sh

@@ -264,7 +264,7 @@ names=$(git log --format='From: %an <%ae>%n%b' --reverse $range |
 	sed -rn 's,.*: (.*<.*@.*>),\1,p' |
 	sort -u)
 bad=$(for contributor in $names ; do
-	contributor=${contributor//(/\\(}
+	contributor=$(echo $contributor | sed 's,(,\\(,')
 	! grep -qE "^$contributor($| <)" $selfdir/../.mailmap || continue
 	name=${contributor%% <*}
 	if grep -q "^$name <" $selfdir/../.mailmap ; then