efi_loader: fix freestanding memmove()

For EFI binaries we have to provide an implementation of memmove() in
efi_freestanding.c.

Before this patch the memmove() function was copying in the wrong
direction.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/efi_freestanding.c b/lib/efi_loader/efi_freestanding.c
index dcf5d1c..bd0dff1 100644
--- a/lib/efi_loader/efi_freestanding.c
+++ b/lib/efi_loader/efi_freestanding.c
@@ -47,7 +47,7 @@
 	u8 *d = dest;
 	const u8 *s = src;
 
-	if (d >= s) {
+	if (d <= s) {
 		for (; n; --n)
 			*d++ = *s++;
 	} else {