make tape tests fail if tape is not available

scripts/functions

@@ -98,23 +98,23 @@ require_tape_drive()
 {
 if test x${TAPE_DRIVE} = x/dev/null ; then
    echo "This test $TestName needs a tape drive, but has none."
-   exit 0
+   exit 1
 fi
 }
 
 require_second_drive()
 {
 if test x${TAPE_DRIVE1} = x/dev/null ; then
    echo "This test $TestName has a Job $JobName which needs a second drive, but has none."
-   exit 0
+   exit 1
 fi
 }
 
 require_autochanger()
 {
 if test x${AUTOCHANGER} = x/dev/null ; then
    echo "This test $TestName needs an autochanger, but has none."
-   exit 0
+   exit 1
 fi
 }
 
@@ -123,15 +123,15 @@ require_linux()
 os=`uname`
 if [ $os != 'Linux' ]; then
    echo "This test $TestName runs only on Linux"
-   exit 0
+   exit 1
 fi
 }
 
 skip_if_no_autochanger()
 {
 if test x${AUTOCHANGER} = x/dev/null ; then
    echo "$TestName test skipped. No autochanger."
-   exit
+   exit 1
 fi
 }