[PATCH] make spin_is_locked use an explicit signed char case

[Christoph Hellwig]

This is a trivial patch from the XFS tree and allows to use spinlock
debugging with code that is compiled with -funsigned-char.  XFS itself
shouldn't need -funsigned-char anymore, but doing the right thing in
spinlock.h doesn't cost anything.

--- linux/include/asm-i386/spinlock.h~	Sun Jun 23 21:38:01 2002
+++ linux/include/asm-i386/spinlock.h	Tue Jun 18 15:10:28 2002
@@ -39,7 +39,7 @@
  * We make no fairness assumptions. They have a cost.
  */
 
-#define spin_is_locked(x)	(*(volatile char *)(&(x)->lock) <= 0)
+#define spin_is_locked(x)	(*(volatile signed char *)(&(x)->lock) <= 0)
 #define spin_unlock_wait(x)	do { barrier(); } while(spin_is_locked(x))
 
 #define spin_lock_string \