net: zynq: Free allocated buffers in case of error

Driver probe function is called again and again in case of error.
Malloc space is getting full which is is reported by:
 Insufficient RAM for page table: 0x15000 > 0x14000.
 Please increase the size in get_page_table_size()
 ### ERROR ### Please RESET the board ###

The patch is freeing allocated buffers on error path to avoid panic.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/net/zynq_gem.c b/drivers/net/zynq_gem.c
index 7f9dc34..5f2f87d 100644
--- a/drivers/net/zynq_gem.c
+++ b/drivers/net/zynq_gem.c
@@ -661,8 +661,10 @@
 
 	/* Align bd_space to MMU_SECTION_SHIFT */
 	bd_space = memalign(1 << MMU_SECTION_SHIFT, BD_SPACE);
-	if (!bd_space)
-		return -ENOMEM;
+	if (!bd_space) {
+		ret = -ENOMEM;
+		goto err1;
+	}
 
 	mmu_set_region_dcache_behaviour((phys_addr_t)bd_space,
 					BD_SPACE, DCACHE_OFF);
@@ -674,7 +676,7 @@
 	ret = clk_get_by_name(dev, "tx_clk", &priv->clk);
 	if (ret < 0) {
 		dev_err(dev, "failed to get clock\n");
-		return -EINVAL;
+		goto err1;
 	}
 
 	priv->bus = mdio_alloc();
@@ -684,9 +686,19 @@
 
 	ret = mdio_register_seq(priv->bus, dev->seq);
 	if (ret)
+		goto err2;
+
+	ret = zynq_phy_init(dev);
+	if (ret)
-		return ret;
+		goto err2;
+
+	return ret;
 
-	return zynq_phy_init(dev);
+err2:
+	free(priv->rxbuffers);
+err1:
+	free(priv->tx_bd);
+	return ret;
 }
 
 static int zynq_gem_remove(struct udevice *dev)