fix build when TRACE is enabled

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19630 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/boot/loader/net/ARP.cpp

@@ -6,6 +6,7 @@
 #include <boot/net/ARP.h>
 
 #include <stdio.h>
+#include <KernelExport.h>
 
 #include <boot/net/ChainBuffer.h>
 

src/system/boot/loader/net/Ethernet.cpp

@@ -6,6 +6,7 @@
 #include <boot/net/Ethernet.h>
 
 #include <stdio.h>
+#include <KernelExport.h>
 
 #include <boot/net/ChainBuffer.h>
 

src/system/boot/loader/net/IP.cpp

@@ -6,6 +6,7 @@
 #include <boot/net/IP.h>
 
 #include <stdio.h>
+#include <KernelExport.h>
 
 #include <boot/net/ARP.h>
 #include <boot/net/ChainBuffer.h>

src/system/boot/loader/net/UDP.cpp

@@ -6,8 +6,7 @@
 #include <boot/net/UDP.h>
 
 #include <stdio.h>
-
+#include <KernelExport.h>
-#include <OS.h>
 
 #include <boot/net/ChainBuffer.h>
 #include <boot/net/NetStack.h>