xen/page-defs: address violation of MISRA C Rule 20.7

MISRA C Rule 20.7 states: "Expressions resulting from the expansion
of macro parameters shall be enclosed in parentheses". Therefore, some
macro definitions should gain additional parentheses to ensure that all
current and future users will be safe with respect to expansions that
can possibly alter the semantics of the passed-in macro parameter.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/include/xen/page-defs.h

@@ -4,7 +4,8 @@
 /* Helpers for different page granularities. */
 #define PAGE_SIZE_GRAN(gran)        ((paddr_t)1 << PAGE_SHIFT_##gran)
 #define PAGE_MASK_GRAN(gran)        (-PAGE_SIZE_GRAN(gran))
-#define PAGE_ALIGN_GRAN(gran, addr) ((addr + ~PAGE_MASK_##gran) & PAGE_MASK_##gran)
+#define PAGE_ALIGN_GRAN(gran, addr) (((addr) + ~PAGE_MASK_##gran) & \
+                                     PAGE_MASK_##gran)
 
 #define PAGE_SHIFT_4K               12
 #define PAGE_SIZE_4K                PAGE_SIZE_GRAN(4K)