phy: tegra: xusb: check return value of devm_kzalloc()

phy: tegra: xusb: check return value of devm_kzalloc()

[ Upstream commit 44faada0f38fc333d392af04c343b0e23f8f5d81 ]

devm_kzalloc() returns a pointer to dynamically allocated memory.
Pointer could be NULL in case allocation fails. Check pointer validity.
Identified with coccinelle (kmerr.cocci script).

Fixes: f67213cee2b3 ("phy: tegra: xusb: Add usb-role-switch support")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20230531073950.145339-1-claudiu.beznea@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>