tests: use "returns_" rather than explicit comparison with "$?"

The previous "returns_"-using change failed to convert many
uses of "$?".  Convert all but two of the remaining ones.
* tests/ls/stat-vs-dirent.sh: Likewise.
* tests/misc/head-write-error.sh: Likewise.
* tests/misc/nice.sh: Likewise.
* tests/misc/nohup.sh: Likewise.
* tests/misc/stdbuf.sh: Likewise.
* tests/misc/sync.sh: Likewise.
* tests/tail-2/pid.sh: Likewise.
* tests/tail-2/wait.sh: Likewise.
Thanks to Bernhard Volker for spotting this.

2 files changed, 8 insertions, 16 deletions

diff --git a/tests/tail-2/pid.sh b/tests/tail-2/pid.sh
index 9e73b8448..ba67b46a6 100755
--- a/tests/tail-2/pid.sh
+++ b/tests/tail-2/pid.sh
@@ -31,8 +31,7 @@ for mode in '' '---disable-inotify'; do
   tail -f $mode here & pid=$!
 
   # Ensure that tail --pid=PID does not exit when PID is alive.
-  timeout 1 tail -f -s.1 --pid=$pid $mode here
-  test $? = 124 || fail=1
+  returns_ 124 timeout 1 tail -f -s.1 --pid=$pid $mode here || fail=1
 
   cleanup_
 
@@ -44,8 +43,7 @@ for mode in '' '---disable-inotify'; do
   test $ret = 0 || fail=1
 
   # Ensure tail doesn't wait for data when PID is dead
-  timeout 10 tail -f -s10 --pid=$PID_T_MAX $mode empty
-  test $? = 124 && fail=1
+  returns_ 124 timeout 10 tail -f -s10 --pid=$PID_T_MAX $mode empty && fail=1
 done
 
 Exit $fail
diff --git a/tests/tail-2/wait.sh b/tests/tail-2/wait.sh
index 59f796abe..1b5432754 100755
--- a/tests/tail-2/wait.sh
+++ b/tests/tail-2/wait.sh
@@ -35,29 +35,23 @@ cleanup_() { kill $pid 2>/dev/null && wait $pid; }
 fastpoll='-s.1 --max-unchanged-stats=1'
 
 for mode in '' '---disable-inotify'; do
-  timeout 10 tail $fastpoll -f $mode not_here
-  test $? = 124 && fail=1
+  returns_ 124 timeout 10 tail $fastpoll -f $mode not_here && fail=1
 
   if test ! -r unreadable; then # can't test this when root
-    timeout 10 tail $fastpoll -f $mode unreadable
-    test $? = 124 && fail=1
+    returns_ 124 timeout 10 tail $fastpoll -f $mode unreadable && fail=1
   fi
 
-  timeout .1 tail $fastpoll -f $mode here 2>tail.err
-  test $? = 124 || fail=1
+  returns_ 124 timeout .1 tail $fastpoll -f $mode here 2>tail.err || fail=1
 
   # 'tail -F' must wait in any case.
 
-  timeout .1 tail $fastpoll -F $mode here 2>>tail.err
-  test $? = 124 || fail=1
+  returns_ 124 timeout .1 tail $fastpoll -F $mode here 2>>tail.err || fail=1
 
   if test ! -r unreadable; then # can't test this when root
-    timeout .1 tail $fastpoll -F $mode unreadable
-    test $? = 124 || fail=1
+    returns_ 124 timeout .1 tail $fastpoll -F $mode unreadable || fail=1
   fi
 
-  timeout .1 tail $fastpoll -F $mode not_here
-  test $? = 124 || fail=1
+  returns_ 124 timeout .1 tail $fastpoll -F $mode not_here || fail=1
 
   grep -Ev "$inotify_failed_re" tail.err > x
   mv x tail.err