actually export iovec

src/header/sys_uio/cbindgen.toml

@@ -2,11 +2,10 @@
 #
 # Spec quotations relating to includes:
 # - "The <sys/uio.h> header shall define the ssize_t and size_t types as described in <sys/types.h>."
-sys_includes = ["sys/types.h"]
+#
+# bits/iovec.h brings in sys/types.h
+sys_includes = ["bits/iovec.h"]
 include_guard = "_SYS_UIO_H"
-after_includes = """
-#include <bits/iovec.h> // for iovec
-"""
 language = "C"
 style = "Tag"
 no_includes = true
@@ -14,3 +13,6 @@ cpp_compat = true
 
 [enum]
 prefix_with_name = true
+
+[export.rename]
+"iovec" = "struct iovec"