disk: Tidy up #ifdefs in part_efi

This file does not correctly handle the various cases, sometimes
producing warnings about partition_basic_data_guid being defined but not
used. Fix it.

There was some discussion about adjusting Kconfig or making
HAVE_BLOCK_DEVICE a prerequisite for PARTITIONS, but apparently this is
not feasible. Such changes can be undertaken separate from the goal of
this series.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/disk/part_efi.c b/disk/part_efi.c
index 0fb7ff0..fdca91a 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -29,12 +29,13 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-/*
- * GUID for basic data partions.
- */
+#ifdef CONFIG_HAVE_BLOCK_DEVICE
+
+/* GUID for basic data partitons */
+#if CONFIG_IS_ENABLED(EFI_PARTITION)
 static const efi_guid_t partition_basic_data_guid = PARTITION_BASIC_DATA_GUID;
+#endif
 
-#ifdef CONFIG_HAVE_BLOCK_DEVICE
 /**
  * efi_crc32() - EFI version of crc32 function
  * @buf: buffer to calculate crc32 of
@@ -1126,4 +1127,4 @@
 	.print		= part_print_ptr(part_print_efi),
 	.test		= part_test_efi,
 };
-#endif
+#endif /* CONFIG_HAVE_BLOCK_DEVICE */