x86: Get rid of dubious one-bit signed bitfield

This very noisy sparse warning appears on almost every file in
the kernel:

  CHECK   init/main.c
  arch/x86/include/asm/thread_info.h:43:55: error: dubious one-bit
  signed bitfield arch/x86/include/asm/thread_info.h:44:46: error:
  dubious one-bit signed bitfield

Sparse is right and this patch changes sig_on_uaccess_error and
uaccess_err flags to unsigned type and thus fixes the warning.
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Acked-by: Andy Lutomirski <luto@mit.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Dan Carpenter <error27@gmail.com>
Link: http://lkml.kernel.org/r/20120111011146.GA30428@oksana.dev.rtsoft.ruSigned-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/thread_info.h

@@ -40,8 +40,8 @@ struct thread_info {
 						*/
 	__u8			supervisor_stack[0];
 #endif
-	int			sig_on_uaccess_error:1;
-	int			uaccess_err:1;	/* uaccess failed */
+	unsigned int		sig_on_uaccess_error:1;
+	unsigned int		uaccess_err:1;	/* uaccess failed */
 };
 
 #define INIT_THREAD_INFO(tsk)			\