usb: dwc3: qcom: Improve error handling

dwc3_qcom_clk_init() is called with of_count_phandle_with_args() as an
argument.  If of_count_phandle_with_args() returns an error, the number
of clocks will be a negative value and will lead to undefined behaviour.

Ensure we check for an error before attempting to blindly use the value.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/dwc3-qcom.c

@@ -409,6 +409,9 @@ static int dwc3_qcom_clk_init(struct dwc3_qcom *qcom, int count)
 	if (!np || !count)
 		return 0;
 
+	if (count < 0)
+		return count;
+
 	qcom->num_clocks = count;
 
 	qcom->clks = devm_kcalloc(dev, qcom->num_clocks,