kdumpctl: check for ssh path availability when rebuild

Currently kdumpctl rebuild will simply rebuild the initramfs, and
only perform basic config syntax check. But it should also check if the
target path is available when using SSH target, else kdump may fail.
is second kernel. kdumpctl rebuild should cover this case, and create
the path if it doesn't exist.

This patch make rebuild and restart behaves the same, rebuild is
now equal to restart, except it won't check config change or reload
kdump resource.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>

kdumpctl

@@ -1174,6 +1174,12 @@ rebuild() {
 		return 1
 	fi
 
+	if check_ssh_config; then
+		if ! check_ssh_target; then
+			return 1
+		fi
+	fi
+
 	setup_initrd
 	if [ $? -ne 0 ]; then
 		return 1