serial: port: Don't suspend if the port is still busy
JIRA: https://issues.redhat.com/browse/RHEL-41060
Signed-off-by: Andrew Halaney ahalaney@redhat.com
JIRA: https://issues.redhat.com/browse/RHEL-41060
Signed-off-by: Andrew Halaney ahalaney@redhat.com