dynamic_debug: remove unused control variables

Remove no longer used dynamic debug control variables. The
definitions were removed a while ago, but we forgot to clean
up the extern references.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/dynamic_debug.h

 #ifndef _DYNAMIC_DEBUG_H
 #define _DYNAMIC_DEBUG_H
 
-/* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which
- * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
- * use independent hash functions, to reduce the chance of false positives.
- */
-extern long long dynamic_debug_enabled;
-extern long long dynamic_debug_enabled2;
-
 /*
  * An instance of this structure is created in a special
  * ELF section at every dynamic debug callsite.  At runtime,