tests: remove obsolete uses of "$$" in temporary file names

Those were useful when tests might have been run in the same
directory and in parallel.  Now, each test is run in a newly-
created empty directory.
* tests/cp/backup-1: Remove obsolete uses of "$$".
* tests/cp/same-file: Likewise.
* tests/dd/misc: Likewise.
* tests/mv/part-symlink: Likewise.
* tests/mv/to-symlink: Likewise.
* tests/touch/fail-diag: Likewise.

tests/cp/backup-1

@@ -21,10 +21,8 @@
 print_ver_ cp
 
 suffix=.b
-file=b1.$$
+file=F
 file_backup="$file$suffix"
-temp_files="$file $file_backup"
-rm -f $temp_files
 
 echo test > $file || fail=1
 

tests/cp/same-file

@@ -39,10 +39,7 @@ test $hard_link_to_symlink_does_the_deref = yes \
     && remove_these_sed='/^0 -[bf]*l .*sl1 ->/d' \
     || remove_these_sed='/^ELIDE NO TEST OUTPUT/d'
 
-actual=actual-$$
-expected=expected-$$
-
-exec 3>&1 1> $actual
+exec 3>&1 1> actual
 
 # FIXME: This should be bigger: like more than 8k
 contents=XYZ
@@ -130,7 +127,7 @@ for args in 'foo symlink' 'symlink foo' 'foo foo' 'sl1 sl2' 'foo hardlink'; do
   echo
 done
 
-cat <<\EOF | sed "$remove_these_sed" > $expected
+cat <<\EOF | sed "$remove_these_sed" > expected
 1 [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
 1 -d [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
 1 -f [cp: `foo' and `symlink' are the same file] (foo symlink -> foo)
@@ -218,6 +215,6 @@ EOF
 
 exec 1>&3 3>&-
 
-compare $expected $actual 1>&2 || fail=1
+compare expected actual 1>&2 || fail=1
 
 Exit $fail

tests/dd/misc

@@ -20,10 +20,10 @@
 . "${srcdir=.}/init.sh"; path_prepend_ ../src
 print_ver_ dd
 
-tmp_in=dd-in.$$
-tmp_in2=dd-in2.$$
-tmp_sym=dd-sym.$$
-tmp_out=dd-out.$$
+tmp_in=dd-in
+tmp_in2=dd-in2
+tmp_sym=dd-sym
+tmp_out=dd-out
 
 warn=0
 echo data > $tmp_in || framework_failure

tests/mv/part-symlink

@@ -45,10 +45,7 @@ pwd_tmp=`pwd`
 # Exercise those four cases for each of
 # cp and mv, with lots of combinations of options.
 
-actual=actual-$$
-expected=expected-$$
-
-exec 1> $actual
+exec 1> actual
 
 # FIXME: This should be bigger: like more than 8k
 contents=XYZ
@@ -153,7 +150,7 @@ done
 test $fail = 1 &&
   { (exit 1); exit; }
 
-cat <<\EOF > $expected
+cat <<\EOF > expected
 1 cp loc_reg rem_sl
  [cp: `loc_reg' and `rem_sl' are the same file]
  (loc_reg) (rem_sl -> dir/loc_reg)
@@ -259,6 +256,6 @@ cat <<\EOF > $expected
 EOF
 
 # Redirect to stderr, since stdout is already taken.
-compare $expected $actual 1>&2 || fail=1
+compare expected actual 1>&2 || fail=1
 
 Exit $fail

tests/mv/to-symlink

@@ -24,10 +24,8 @@ cleanup_() { rm -rf "$other_partition_tmpdir"; }
 
 rem_file="$other_partition_tmpdir/file"
 rem_symlink="$other_partition_tmpdir/symlink"
-file=to-sym-$$
+file=to-sym
 
-
-rm -f $file || framework_failure
 echo local > $file || framework_failure
 echo remote > $rem_file || framework_failure
 ln -s $rem_file $rem_symlink || framework_failure

tests/touch/fail-diag

@@ -20,15 +20,11 @@
 print_ver_ touch
 skip_if_root_
 
-d1=no-$$
-dir=/$d1/such-dir
-# Ensure that $d1 doesn't already exist.
-ls -d $d1 2> /dev/null && framework_failure
+file=/no-such-dir/file
 
-
-touch $dir > out 2>&1 && fail=1
+touch $file > out 2>&1 && fail=1
 cat <<EOF > exp
-touch: cannot touch \`$dir': No such file or directory
+touch: cannot touch \`$file': No such file or directory
 EOF
 
 compare out exp || fail=1