clk: bcm: rpi: Add NULL check in raspberrypi_clk_register()

devm_kasprintf() returns NULL when memory allocation fails. Currently,
raspberrypi_clk_register() does not check for this case, which results
in a NULL pointer dereference.

Add NULL check after devm_kasprintf() to prevent this issue.

Fixes: 93d2725affd6 ("clk: bcm: rpi: Discover the firmware clocks")
Signed-off-by: Henry Martin <[e-mail]>
Reviewed-by: Dave Stevenson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Stefan Wahren <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/bcm/clk-raspberrypi.c

···
 	init.name = devm_kasprintf(rpi->dev, GFP_KERNEL,
 				   "fw-clk-%s",
 				   rpi_firmware_clk_names[id]);
+	if (!init.name)
+		return ERR_PTR(-ENOMEM);
 	init.ops = &raspberrypi_firmware_clk_ops;
 	init.flags = CLK_GET_RATE_NOCACHE;