bus: mhi: core: Fix some error return code

Fix to return negative error code from the error handling case
instead of 0 in mhi_init_dev_ctxt() and mhi_driver_probe().

Fixes: 3000f85b ("bus: mhi: core: Add support for basic PM operations")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200509075654.175002-1-weiyongjun1@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/core/init.c

@@ -291,6 +291,7 @@ int mhi_init_dev_ctxt(struct mhi_controller *mhi_cntrl)
 	}
 
 	/* Setup cmd context */
+	ret = -ENOMEM;
 	mhi_ctxt->cmd_ctxt = mhi_alloc_coherent(mhi_cntrl,
 						sizeof(*mhi_ctxt->cmd_ctxt) *
 						NR_OF_CMD_RINGS,
@@ -1100,6 +1101,7 @@ static int mhi_driver_probe(struct device *dev)
 		}
 	}
 
+	ret = -EINVAL;
 	if (dl_chan) {
 		/*
 		 * If channel supports LPM notifications then status_cb should