test: print NMTST_SEED_RAND value with g_print()

For tests with assert-logging enabled, we already printed
the message with g_print(), instead of g_message().

We always want to print this value, because it is important
to reproduce a test failure. Hence, just (always) print
directly to stdout.

Also, add a leading newline, because the output was attached
to the previous line.

(cherry picked from commit 4ab540939c)

include/nm-test-utils.h

@@ -493,7 +493,7 @@ nmtst_get_rand (void)
 		}
 		__nmtst_internal.rand_seed = seed;
 
-		__NMTST_LOG (g_message, ">> initialize nmtst_get_rand() with NMTST_SEED_RAND=%u", seed);
+		g_print ("\nnmtst: initialize nmtst_get_rand() with NMTST_SEED_RAND=%u\n", seed);
 	}
 	return __nmtst_internal.rand;
 }