efi_loader: handle malloc() errors

The new_packagelist() function of the HII Protocols implementation is
calling malloc() without checking its return code; fix this.

Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

lib/efi_loader/efi_hii.c

@@ -343,6 +343,9 @@ static struct efi_hii_packagelist *new_packagelist(void)
 	struct efi_hii_packagelist *hii;
 
 	hii = malloc(sizeof(*hii));
+	if (!hii)
+		return NULL;
+
 	list_add_tail(&hii->link, &efi_package_lists);
 	hii->max_string_id = 0;
 	INIT_LIST_HEAD(&hii->string_tables);