[lib] Free pages using the correct method

Pages should be freed with FreePages rather than FreePool.

Change-Id: Id5d3808550cce2f947da448efcd3e5d94e6b65fd
diff --git a/lib/loadfile.c b/lib/loadfile.c
index c8cd9be..aad14ea 100644
--- a/lib/loadfile.c
+++ b/lib/loadfile.c
@@ -67,13 +67,13 @@
     r = file->Read(file, &sz, data);
     if (r) {
         printf("LoadFile: Error reading file (%s)\n", efi_strerror(r));
-        gBS->FreePool(data);
+        gBS->FreePages((EFI_PHYSICAL_ADDRESS)data, pages);
         data = NULL;
         goto exit4;
     }
     if (sz != finfo->FileSize) {
         printf("LoadFile: Short read\n");
-        gBS->FreePool(data);
+        gBS->FreePages((EFI_PHYSICAL_ADDRESS)data, pages);
         data = NULL;
         goto exit4;
     }