arm64: booti: add missing unmap_sysmem()

Make sure to call unmap_sysmem() for address allocated by map_sysmem()
before leaving the function; however this patch gives no impact on
the behavior because map_sysmem()/unmap_sysmem() does nothing except
on Sandbox.  Sandbox never runs this code because "booti" is a command
for booting ARM64 kernel image.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/cmd/bootm.c b/cmd/bootm.c
index 555ccbc..1bca6fa 100644
--- a/cmd/bootm.c
+++ b/cmd/bootm.c
@@ -673,6 +673,9 @@
 	 * correct location and then move the image there.
 	 */
 	dst = gd->bd->bi_dram[0].start + le32_to_cpu(ih->text_offset);
+
+	unmap_sysmem(ih);
+
 	if (images->ep != dst) {
 		void *src;
 
@@ -717,6 +720,8 @@
 
 	lmb_reserve(&images->lmb, images->ep, le32_to_cpu(ih->image_size));
 
+	unmap_sysmem(ih);
+
 	/*
 	 * Handle the BOOTM_STATE_FINDOTHER state ourselves as we do not
 	 * have a header that provide this informaiton.