usb: fsl: Check memory resource before releasing it

usb: fsl: Check memory resource before releasing it

BugLink: https://bugs.launchpad.net/bugs/1852338
[ Upstream commit bc1e3a2dd0c9954fd956ac43ca2876bbea018c01 ]

Check memory resource existence before releasing it to avoid NULL
pointer dereference

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Reviewed-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>