disk: Drop always true conditional check

if (device_get_uclass_id(dev) == UCLASS_PARTITION) is always
true, because this disk_blk_read() function calls dev_get_blk()
above and checks its return value for non-NULL. The dev_get_blk()
performs the same device_get_uclass_id(dev) check and returns NULL
if not UCLASS_PARTITION. Drop the duplicate check.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/disk/disk-uclass.c b/disk/disk-uclass.c
index d32747e..5974dd8 100644
--- a/disk/disk-uclass.c
+++ b/disk/disk-uclass.c
@@ -186,10 +186,8 @@
 		return -ENOSYS;
 
 	start_in_disk = start;
-	if (device_get_uclass_id(dev) == UCLASS_PARTITION) {
-		part = dev_get_uclass_plat(dev);
-		start_in_disk += part->gpt_part_info.start;
-	}
+	part = dev_get_uclass_plat(dev);
+	start_in_disk += part->gpt_part_info.start;
 
 	if (blkcache_read(desc->uclass_id, desc->devnum, start_in_disk, blkcnt,
 			  desc->blksz, buffer))