efi_loader: avoid multiple local copies of lf2_initrd_guid

Create the GUID as a global variable.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

include/efi_load_initrd.h

@@ -16,6 +16,7 @@
 #define EFI_INITRD_MEDIA_GUID \
 	EFI_GUID(0x5568e427, 0x68fc, 0x4f3d, \
 		 0xac, 0x74, 0xca, 0x55, 0x52, 0x31, 0xcc, 0x68)
+extern const efi_guid_t efi_lf2_initrd_guid;
 
 struct efi_initrd_dp {
 	struct efi_device_path_vendor vendor;