Error compiling libctf-regression test

Seen on 64-bit targets.
ERROR: compilation of lookup program .../libctf-regression/gzrewrite.c failed

	* testsuite/libctf-regression/gzrewrite.c (main): Use %zu to
	print size_t values.
	* testsuite/libctf-regression/zrewrite.c (main): Likewise.
diff --git a/libctf/testsuite/libctf-regression/gzrewrite.c b/libctf/testsuite/libctf-regression/gzrewrite.c
index 8e279ca..9972220 100644
--- a/libctf/testsuite/libctf-regression/gzrewrite.c
+++ b/libctf/testsuite/libctf-regression/gzrewrite.c
@@ -88,7 +88,7 @@
 
   if (a_len != b_len || memcmp (a, b, a_len) != 0)
     {
-      fprintf (stderr, "consecutive gzwrites are different: lengths %i and %i\n", a_len, b_len);
+      fprintf (stderr, "consecutive gzwrites are different: lengths %zu and %zu\n", a_len, b_len);
       return 1;
     }
 
diff --git a/libctf/testsuite/libctf-regression/zrewrite.c b/libctf/testsuite/libctf-regression/zrewrite.c
index 4d5d15e..a88c824 100644
--- a/libctf/testsuite/libctf-regression/zrewrite.c
+++ b/libctf/testsuite/libctf-regression/zrewrite.c
@@ -83,7 +83,7 @@
 
   if (a_len != b_len || memcmp (a, b, a_len) != 0)
     {
-      fprintf (stderr, "consecutive compress_writes are different: lengths %i and %i\n", a_len, b_len);
+      fprintf (stderr, "consecutive compress_writes are different: lengths %zu and %zu\n", a_len, b_len);
       return 1;
     }