efi_loader: make get_load_options() static

In program initrddump.efi function get_load_options() can be static.

This avoids a warning when building with 'make W=1':

    lib/efi_loader/initrddump.c:442:6: warning:
    no previous prototype for ‘get_load_options’ [-Wmissing-prototypes]
      442 | u16 *get_load_options(void)
          |      ^~~~~~~~~~~~~~~~

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/initrddump.c b/lib/efi_loader/initrddump.c
index 9872106..971a3b6 100644
--- a/lib/efi_loader/initrddump.c
+++ b/lib/efi_loader/initrddump.c
@@ -439,7 +439,7 @@
  *
  * Return:	load options or NULL
  */
-u16 *get_load_options(void)
+static u16 *get_load_options(void)
 {
 	efi_status_t ret;
 	struct efi_loaded_image *loaded_image;