efi_loader: use correct documentation style

We have moved generating html documentation with Sphinx.

%s/Return Value/Return/g

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_loader/efi_boottime.c

@@ -3124,7 +3124,7 @@ struct efi_system_table __efi_runtime_data systab = {
 /**
  * efi_initialize_system_table() - Initialize system table
  *
- * Return Value:        status code
+ * Return:	status code
  */
 efi_status_t efi_initialize_system_table(void)
 {