x86 ptrace: fix ptrace_bts_config structure declaration

The 2.6.25 ptrace_bts_config structure in asm-x86/ptrace-abi.h
is defined with u32 types:

   #include <asm/types.h>

   /* configuration/status structure used in PTRACE_BTS_CONFIG and
      PTRACE_BTS_STATUS commands.
   */
   struct ptrace_bts_config {
           /* requested or actual size of BTS buffer in bytes */
           u32 size;
           /* bitmask of below flags */
           u32 flags;
           /* buffer overflow signal */
           u32 signal;
           /* actual size of bts_struct in bytes */
           u32 bts_size;
   };
   #endif

But u32 is only accessible in asm-x86/types.h if __KERNEL__,
leading to compile errors when ptrace.h is included from
user-space. The double-underscore versions that are exported
to user-space in asm-x86/types.h should be used instead.

Signed-off-by: Dave Anderson <anderson@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>