tests: modernise style: more uses of test_line_count

Prefer:

  test_line_count <OP> COUNT FILE

over:

  test $(wc -l <FILE) <OP> COUNT

(or similar usages) in several tests.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t9400-git-cvsserver-server.sh b/t/t9400-git-cvsserver-server.sh
index 9199550..d3e88f8 100755
--- a/t/t9400-git-cvsserver-server.sh
+++ b/t/t9400-git-cvsserver-server.sh
@@ -476,14 +476,14 @@
     cd cvswork &&
     GIT_CONFIG="$git_config" cvs update &&
     GIT_CONFIG="$git_config" cvs status | grep "^File: status.file" >../out &&
-    test $(wc -l <../out) = 2
+    test_line_count = 2 ../out
 '
 
 cd "$WORKDIR"
 test_expect_success 'cvs status (nonrecursive)' '
     cd cvswork &&
     GIT_CONFIG="$git_config" cvs status -l | grep "^File: status.file" >../out &&
-    test $(wc -l <../out) = 1
+    test_line_count = 1 ../out
 '
 
 cd "$WORKDIR"