docs: fault-injection: drop reference to md-faulty

Commit 415c745 ("md: Remove deprecated CONFIG_MD_FAULTY") removed
the md-faulty driver, so drop the outdated reference from the
fault-injection documentation.

Signed-off-by: Vignesh Raman <vignesh.raman@collabora.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250723102835.232740-1-vignesh.raman@collabora.com

Author: vigneshraman

Documentation/fault-injection/fault-injection.rst

@@ -2,7 +2,7 @@
 Fault injection capabilities infrastructure
 ===========================================
 
-See also drivers/md/md-faulty.c and "every_nth" module option for scsi_debug.
+See also "every_nth" module option for scsi_debug.
 
 
 Available fault injection capabilities