xen/include: address violations 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>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/include/xen/bug.h

@@ -80,7 +80,7 @@ struct bug_frame {
     [bf_type]    "i" (type),                                                 \
     [bf_ptr]     "i" (ptr),                                                  \
     [bf_msg]     "i" (msg),                                                  \
-    [bf_line_lo] "i" ((line & ((1 << BUG_LINE_LO_WIDTH) - 1))                \
+    [bf_line_lo] "i" (((line) & ((1 << BUG_LINE_LO_WIDTH) - 1))              \
                       << BUG_DISP_WIDTH),                                    \
     [bf_line_hi] "i" (((line) >> BUG_LINE_LO_WIDTH) << BUG_DISP_WIDTH)
 

xen/include/xen/init.h

@@ -63,9 +63,9 @@ typedef int (*initcall_t)(void);
 typedef void (*exitcall_t)(void);
 
 #define presmp_initcall(fn) \
-    const static initcall_t __initcall_##fn __init_call("presmp") = fn
+    const static initcall_t __initcall_##fn __init_call("presmp") = (fn)
 #define __initcall(fn) \
-    const static initcall_t __initcall_##fn __init_call("1") = fn
+    const static initcall_t __initcall_##fn __init_call("1") = (fn)
 #define __exitcall(fn) \
     static exitcall_t __exitcall_##fn __exit_call = fn