Linux 2.6.39 compat, zlib_deflate_workspacesize()

The function zlib_deflate_workspacesize() now take 2 arguments.
This was done to avoid always having to allocate the maximum size
workspace (268K).  The caller can now specific the windowBits and
memLevel compression parameters to get a smaller workspace.

For our purposes we introduce a spl_zlib_deflate_workspacesize()
wrapper which accepts both arguments.  When the two argument
version of zlib_deflate_workspacesize() is available the arguments
are passed through.  When it's not we assume the worst case and
a maximally sized workspace is used.

include/sys/types.h

@@ -41,6 +41,7 @@
 #include <linux/sysctl_compat.h>
 #include <linux/proc_compat.h>
 #include <linux/math64_compat.h>
+#include <linux/zlib_compat.h>
 
 #ifndef HAVE_UINTPTR_T
 typedef unsigned long			uintptr_t;