Minor fix

@@ -23,9 +23,10 @@ AT_KEYWORDS([columns cols00])
 #    http://lists.gnu.org/archive/html/bug-mailutils/2015-04/msg00002.html
 
 AT_CHECK([
+MUT_MBCOPY($abs_top_srcdir/testsuite/spool/mbox)
 unset MAILRC
-COLUMNS=26 mail -nH -E 'set columns=26' -f $testsuitedir/spool/mbox
-COLUMNS=31 mail -nH -f $testsuitedir/spool/mbox
+COLUMNS=26 mail -nH -E 'set columns=26' -f ./mbox
+COLUMNS=31 mail -nH -f ./mbox
 ],
 [0],
 [>N   1 Sergey Poznyakoff

@@ -23,9 +23,10 @@ AT_KEYWORDS([columns cols01])
 #   http://lists.gnu.org/archive/html/bug-mailutils/2015-04/msg00000.html
 
 AT_CHECK([
+MUT_MBCOPY($abs_top_srcdir/testsuite/spool/mbox)
 unset MAILRC
-mail -nH -E 'set columns=26' -f $testsuitedir/spool/mbox
-mail -nH -E 'set columns=31' -f $testsuitedir/spool/mbox
+mail -nH -E 'set columns=26' -f ./mbox
+mail -nH -E 'set columns=31' -f ./mbox
 ],
 [0],
 [>N   1 Sergey Poznyakoff

@@ -24,8 +24,9 @@ AT_KEYWORDS([copy copy00])
 
 AT_CHECK([
 test -f /dev/stdout || AT_SKIP_TEST
+MUT_MBCOPY($abs_top_srcdir/testsuite/spool/mbox)
 unset MAILRC
-echo 'copy 1 /dev/stdout' | mail -N -E 'set readonly' -f $testsuitedir/spool/mbox | sed 's/  *$//;/^Held 1 message/d';
+echo 'copy 1 /dev/stdout' | mail -N -E 'set readonly' -f ./mbox | sed 's/  *$//;/^Held 1 message/d';
 ],
 [0],
 [From gray@example.net Tue Jul 16 12:11:35 2002

@@ -23,9 +23,10 @@ AT_KEYWORDS([nohome])
 #    http://lists.gnu.org/archive/html/bug-mailutils/2015-04/msg00002.html 
 
 AT_CHECK([
+MUT_MBCOPY($abs_top_srcdir/testsuite/spool/mbox)
 unset MAILRC
 unset HOME
-MAIL=$testsuitedir/spool/mbox mail -nH
+MAIL=./mbox mail -nH
 ],
 [0],
 [>N   1 Sergey Poznyakoff  Tue Jul 16 12:11  12/390   MBOX