[AVR32] ssize_t should be long, not int

Since size_t is defined as unsigned long, ssize_t ought to be long
and not int. It could have been the other way around, but gcc defines
size_t as unsigned long, so this is correct.

This fixes a couple of printk format warnings.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

include/asm-avr32/posix_types.h

@@ -23,7 +23,7 @@ typedef unsigned short  __kernel_ipc_pid_t;
 typedef unsigned int	__kernel_uid_t;
 typedef unsigned int	__kernel_gid_t;
 typedef unsigned long	__kernel_size_t;
-typedef int             __kernel_ssize_t;
+typedef long		__kernel_ssize_t;
 typedef int             __kernel_ptrdiff_t;
 typedef long            __kernel_time_t;
 typedef long            __kernel_suseconds_t;