efi_loader: remove empty comment line

Remove a line leading to a warning in make htmldocs.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/efi_variable.h b/include/efi_variable.h
index 60491cb..4704a3c 100644
--- a/include/efi_variable.h
+++ b/include/efi_variable.h
@@ -274,7 +274,6 @@
  * @data:		buffer to which the variable value is copied
  * @timep:		authentication time (seconds since start of epoch)
  * Return:		status code
-
  */
 efi_status_t __efi_runtime
 efi_get_variable_mem(u16 *variable_name, const efi_guid_t *vendor, u32 *attributes,