drm/pl111: pl111_vexpress.c: Add of_node_put() before return

Each iteration of for_each_available_child_of_node puts the previous
node, but in the case of a break from the middle of the loop there is
no put, thus causing a memory leak. Hence add an of_node_put before the
break.
Issue found with Coccinelle.

Signed-off-by: Nishka Dasgupta <[e-mail]>
Signed-off-by: Eric Anholt <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/pl111/pl111_vexpress.c

···
 		}
 		if (of_device_is_compatible(child, "arm,hdlcd")) {
 			has_coretile_hdlcd = true;
+			of_node_put(child);
 			break;
 		}
 	}