arch/tile: fix gcc 4.6 warnings in <asm/bitops_64.h>

Fix some signedness and variable usage warnings in change_bit()
and test_and_change_bit().

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/include/asm/bitops_64.h b/arch/tile/include/asm/bitops_64.h
index 58d021a..60b87ee 100644
--- a/arch/tile/include/asm/bitops_64.h
+++ b/arch/tile/include/asm/bitops_64.h
@@ -38,10 +38,10 @@
 
 static inline void change_bit(unsigned nr, volatile unsigned long *addr)
 {
-	unsigned long old, mask = (1UL << (nr % BITS_PER_LONG));
-	long guess, oldval;
+	unsigned long mask = (1UL << (nr % BITS_PER_LONG));
+	unsigned long guess, oldval;
 	addr += nr / BITS_PER_LONG;
-	old = *addr;
+	oldval = *addr;
 	do {
 		guess = oldval;
 		oldval = atomic64_cmpxchg((atomic64_t *)addr,
@@ -85,7 +85,7 @@
 				      volatile unsigned long *addr)
 {
 	unsigned long mask = (1UL << (nr % BITS_PER_LONG));
-	long guess, oldval = *addr;
+	unsigned long guess, oldval;
 	addr += nr / BITS_PER_LONG;
 	oldval = *addr;
 	do {