kernel32: Remove unused Wine debug channel

[Andrew Talbot]

Changelog:
    kernel32: Remove unused Wine debug channel.

diff --git a/dlls/kernel32/fiber.c b/dlls/kernel32/fiber.c
index fda5f92..f828cdc 100644
--- a/dlls/kernel32/fiber.c
+++ b/dlls/kernel32/fiber.c
@@ -34,9 +34,6 @@
 #include "winternl.h"
 #include "wine/exception.h"
 #include "wine/library.h"
-#include "wine/debug.h"
-
-WINE_DEFAULT_DEBUG_CHANNEL(fiber);
 
 struct fiber_data
 {