bitops: Add missing parentheses to new get_order macro

The new get_order macro introcuded in commit

d66acc39c7cee323733c8503b9de1821a56dff7e

does not use parentheses around all uses of the parameter n.
This causes new compile warnings, for example in the
amd_iommu_init.c function:

drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses]
drivers/iommu/amd_iommu_init.c:561:6: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses]

Fix those warnings by adding the missing parentheses.

Reported-by: Ingo Molnar <[e-mail]>
Cc: David Howells <[e-mail]>
Acked-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Joerg Roedel <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: H. Peter Anvin <[e-mail]>

include/asm-generic/getorder.h

···
 #define get_order(n)						\
 (								\
 	__builtin_constant_p(n) ? (				\
-		(n == 0UL) ? BITS_PER_LONG - PAGE_SHIFT :	\
-		((n < (1UL << PAGE_SHIFT)) ? 0 :		\
+		((n) == 0UL) ? BITS_PER_LONG - PAGE_SHIFT :	\
+		(((n) < (1UL << PAGE_SHIFT)) ? 0 :		\
 		 ilog2((n) - 1) - PAGE_SHIFT + 1)		\
 	) :							\
 	__get_order(n)						\