MDEV-31467: wsrep_sst_mariabackup not working on FreeBSD

Due to the different command line format of the timeout
utility on FreeBSD and Linux, SST scripts for mariabackup
may not work on FreeBSD. This commit fixes this problem
by adding a different command to test options on FreeBSD
and adding proper formatting for the utility options.

scripts/wsrep_sst_mariabackup.sh

@@ -798,10 +798,20 @@ recv_joiner()
     local ltcmd="$tcmd"
     if [ $tmt -gt 0 ]; then
         if [ -n "$(commandex timeout)" ]; then
-            if timeout --help | grep -qw -F -- '-k'; then
+            local koption=0
+            if [ "$OS" = 'FreeBSD' ]; then
+                if timeout 2>&1 | grep -qw -F -- '-k'; then
+                    koption=1
+                fi
+            else
+                if timeout --help | grep -qw -F -- '-k'; then
+                    koption=1
+                fi
+            fi
+            if [ $koption -ne 0 ]; then
                 ltcmd="timeout -k $(( tmt+10 )) $tmt $tcmd"
             else
-                ltcmd="timeout -s9 $tmt $tcmd"
+                ltcmd="timeout -s 9 $tmt $tcmd"
             fi
         fi
     fi