Use `rm', not $RM. Use better trap.

tests/rm/f-1

@@ -1,15 +1,16 @@
 #!/bin/sh
 
-: ${RM=rm}
 test=f-1
 
 if test "$VERBOSE" = yes; then
   set -x
-  $RM --version
+  rm --version
 fi
 
-: ${RM_TMPDIR=.}
-tmp=$RM_TMPDIR/t-rm.$$
+pwd=`pwd`
+tmp=`echo "$0"|sed 's,.*/,,'`.tmp
+trap 'status=$?; cd $pwd; rm -rf $tmp && exit $status' 0
+trap '(exit $?); exit' 1 2 13 15
 
 test_failure=0
 mkdir $tmp || test_failure=1
@@ -20,7 +21,6 @@ if test $test_failure = 1; then
 fi
 
 fail=0
-$RM -f $tmp/no-such-file || fail=1
-rm -rf $tmp
+rm -f $tmp/no-such-file || fail=1
 
 exit $fail