trivial: update broken URLs in Documentation/filesystems

update several broken URLs in Documentation/filesystems.

---

Documentation/filesystems/befs.txt  |    4 ++--
Documentation/filesystems/ext2.txt  |    2 +-
Documentation/filesystems/ext3.txt  |    4 ++--
Documentation/filesystems/isofs.txt |    2 +-
4 files changed, 6 insertions(+), 6 deletions(-)

index 67391a1..ea954f2 100644
@@ -61,7 +61,7 @@ step 2.  Configuration & make kernel
 

The linux kernel has many compile-time options. Most of them are beyond the scope of this document. I suggest the Kernel-HOWTO document as a good general -reference on this topic. <http://www.linux.com/howto/Kernel-HOWTO.html>
+reference on this topic. <http://www.linuxdocs.org/HOWTOs/Kernel-HOWTO.html>

However, to use the BeFS module, you must enable it at configure time.

@@ -79,7 +79,7 @@ Save your kernel configuration and then build your kernel.

step 3. Install

-See the kernel howto <http://www.linux.com/howto/Kernel-HOWTO.html> for +See the kernel howto <http://www.linuxdocs.org/HOWTOs/Kernel-HOWTO.html> for instructions on this critical step.

USING BFS

index 4333e83..e1dbcaa 100644
@@ -377,6 +377,6 @@ Windows 95/98/NT/2000	http://uranus.it.swin.edu.au/~jn/linux/Explore2fs.htm

Windows 95 (*) http://www.yipton.demon.co.uk/content.html#FSDEXT2
DOS client (*) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/
OS/2 http://perso.wanadoo.fr/matthieu.willm/ext2-os2/
-RISC OS client ftp://ftp.barnet.ac.uk/pub/acorn/armlinux/iscafs/
+RISC OS client http://www.esw-heim.tu-clausthal.de/~marco/smorbrod/IscaFS/

(*) no longer actively developed/supported (as of Apr 2001)

index 4aecc9b..37aaa22 100644
@@ -194,5 +194,5 @@ programs: 	http://e2fsprogs.sourceforge.net/

http://ext2resize.sourceforge.net

useful links: http://www.zip.com.au/~akpm/linux/ext3/ext3-usage.html
- http://www-106.ibm.com/developerworks/linux/library/l-fs7/
- http://www-106.ibm.com/developerworks/linux/library/l-fs8/
+ http://www.ibm.com/developerworks/linux/library/l-fs7.html
+ http://www.ibm.com/developerworks/linux/library/l-fs8.html

index 758e504..9c93324 100644
@@ -36,7 +36,7 @@ Mount options unique to the isofs filesystem.
 

Recommended documents about ISO 9660 standard are located at:
http://www.y-adagio.com/public/standards/iso_cdromr/tocont.htm
-ftp://ftp.ecma.ch/ecma-st/Ecma-119.pdf
+http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-119.pdf
Quoting from the PDF "This 2nd Edition of Standard ECMA-119 is technically identical with ISO 9660.", so it is a valid and gratis substitute of the official ISO specification.

1.5.0.6