MDEV-32158: wsrep_sst_mariabackup use /tmp dir during SST rather then user defined tmpdir

wsrep_sst_mariabackup should use the tmpdir defined by
the user under the '[mysqld]' section of the configuration
file rather than the default '/tmp' directory.

scripts/wsrep_sst_mariabackup.sh

@@ -714,7 +714,7 @@ cleanup_at_exit()
     fi
 
     # Final cleanup
-    pgid=$(ps -o pgid= $$ 2>/dev/null | grep -o -E '[0-9]+' || :)
+    pgid=$(ps -o 'pgid=' $$ 2>/dev/null | grep -o -E '[0-9]+' || :)
 
     # This means no setsid done in mysqld.
     # We don't want to kill mysqld here otherwise.
@@ -1086,17 +1086,19 @@ if [ "$WSREP_SST_OPT_ROLE" = 'donor' ]; then
         tmpdir=$(parse_cnf "$encgroups" 'tmpdir')
         if [ -z "$tmpdir" ]; then
             xtmpdir="$(mktemp -d)"
+            itmpdir="$(mktemp -d)"
         elif [ "$OS" = 'Linux' ]; then
-            xtmpdir=$(mktemp '-d' "--tmpdir=$tmpdir")
+            xtmpdir=$(mktemp -d "--tmpdir=$tmpdir")
+            itmpdir=$(mktemp -d "--tmpdir=$tmpdir")
         else
-            xtmpdir=$(TMPDIR="$tmpdir"; mktemp '-d')
+            xtmpdir=$(TMPDIR="$tmpdir"; mktemp -d)
+            itmpdir=$(TMPDIR="$tmpdir"; mktemp -d)
         fi
 
         wsrep_log_info "Using '$xtmpdir' as mariadb-backup temporary directory"
         tmpopts=" --tmpdir='$xtmpdir'"
 
-        itmpdir="$(mktemp -d)"
-        wsrep_log_info "Using '$itmpdir' as mariadb-abackup working directory"
+        wsrep_log_info "Using '$itmpdir' as mariadb-backup working directory"
 
         usrst=0
         if [ -n "$WSREP_SST_OPT_USER" ]; then