efi_loader: avoid initializer element is not constant

When building with -pedantic the current definition of EFI_GUID() causes
an error 'initializer element is not constant'.

Currently EFI_GUID() is used both as an anonymous constant and as an
intializer. A conversion to efi_guid_t is not allowable when using
EFI_GUID() as an initializer. But it is needed when using it as an
anonymous constant.

We should not use EFI_GUID() for anything but an initializer. So let's
introduce a variable where needed and remove the conversion.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/include/efi.h b/include/efi.h
index 98bddba..e30a3c5 100644
--- a/include/efi.h
+++ b/include/efi.h
@@ -89,12 +89,11 @@
 typedef void *efi_handle_t;
 
 #define EFI_GUID(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) \
-	((efi_guid_t) \
 	{{ (a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, \
 		((a) >> 24) & 0xff, \
 		(b) & 0xff, ((b) >> 8) & 0xff, \
 		(c) & 0xff, ((c) >> 8) & 0xff, \
-		(d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } })
+		(d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) } }
 
 /* Generic EFI table header */
 struct efi_table_hdr {