usb: phy: am335x-control: check return value of bus_find_device
usb: phy: am335x-control: check return value of bus_find_device

This fixes a potential null pointer dereference.

Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org> # v3.16+
Fixes: d4332013919a ("driver core: dev_get_drvdata: Don't check for NULL dev")
Acked-by: Sebastian Andrzej Siewior <265264fed90bdf8e813a354375ec16f47ebdb1c5@linutronix.de>
Signed-off-by: David Dueck <bb4994c42dd94507deff83e5b578b99946960e88@googlemail.com>
Signed-off-by: Felipe Balbi <94dddeeef08b001e003cce128ddc162a4e2c6cd2@ti.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs