[PATCH 4/5] rt2x00: Compiler warning unmasked by fix of BUILD_BUG_ON

[Boaz Harrosh <bharrosh@panasas.com>]

A "Set" of the sign-bit in an "&" operation causes a compiler warning.
Make calculations unsigned.

[ The warning was masked by the use of (void)() cast in the old
  BUILD_BUG_ON() ]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
TO: Ivo van Doorn <IvDoorn@gmail.com>
TO: John W. Linville <linville@tuxdriver.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/net/wireless/rt2x00/rt2x00reg.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00reg.h b/drivers/net/wireless/rt2x00/rt2x00reg.h
index 7e88ce5..c0e8706 100644
--- a/drivers/net/wireless/rt2x00/rt2x00reg.h
+++ b/drivers/net/wireless/rt2x00/rt2x00reg.h
@@ -134,8 +134,8 @@ struct rt2x00_field32 {
  * Note that we cannot use the is_power_of_2() function since this
  * check must be done at compile-time.
  */
-#define is_power_of_two(x)	( !((x) & ((x)-1)) )
-#define low_bit_mask(x)		( ((x)-1) & ~(x) )
+#define is_power_of_two(x)	( !((unsigned)(x) & ((x)-1)) )
+#define low_bit_mask(x)		( ((unsigned)(x)-1) & ~(x) )
 #define is_valid_mask(x)	is_power_of_two(1 + (x) + low_bit_mask(x))
 
 /*