maint: fix dd nocache test to be independent of current stdin

* tests/dd/nocache: Don't assume stdin is a pipe

diff --git a/tests/dd/nocache b/tests/dd/nocache
index b0d4cc1..b5afabd 100755 (executable)
--- a/tests/dd/nocache
+++ b/tests/dd/nocache
@@ -23,7 +23,7 @@ print_ver_ dd
 dd iflag=nocache oflag=nocache if=/dev/null of=/dev/null || fail=1
 
 # We should get an error for trying to process a pipe
-dd iflag=nocache count=0 && fail=1
+dd count=0 | dd iflag=nocache count=0 && fail=1
 
 # O_DIRECT is orthogonal to drop cache so mutually exclusive
 dd iflag=nocache,direct if=/dev/null && fail=1