Document kernel taint flags properly

This fills in the documentation for all of the current kernel taint
flags, and fixes the number for TAINT_CRAP, which was incorrectly
described.

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/sysctl/kernel.txt

@@ -363,11 +363,21 @@ tainted:
 Non-zero if the kernel has been tainted.  Numeric values, which
 can be ORed together:
 
-  1 - A module with a non-GPL license has been loaded, this
-      includes modules with no license.
-      Set by modutils >= 2.4.9 and module-init-tools.
-  2 - A module was force loaded by insmod -f.
-      Set by modutils >= 2.4.9 and module-init-tools.
-  4 - Unsafe SMP processors: SMP with CPUs not designed for SMP.
- 64 - A module from drivers/staging was loaded.
+   1 - A module with a non-GPL license has been loaded, this
+       includes modules with no license.
+       Set by modutils >= 2.4.9 and module-init-tools.
+   2 - A module was force loaded by insmod -f.
+       Set by modutils >= 2.4.9 and module-init-tools.
+   4 - Unsafe SMP processors: SMP with CPUs not designed for SMP.
+   8 - A module was forcibly unloaded from the system by rmmod -f.
+  16 - A hardware machine check error occurred on the system.
+  32 - A bad page was discovered on the system.
+  64 - The user has asked that the system be marked "tainted".  This
+       could be because they are running software that directly modifies
+       the hardware, or for other reasons.
+ 128 - The system has died.
+ 256 - The ACPI DSDT has been overridden with one supplied by the user
+        instead of using the one provided by the hardware.
+ 512 - A kernel warning has occurred.
+1024 - A module from drivers/staging was loaded.