x86/domain: address Misra rule 11.1 violation in reset_stack_and_call_ind()

Eclair dislikes both sides of the comparison to differ in noreturn
attributes, thus deeming this a violation of "Conversions shall not be
performed between a pointer to a function and any other type". Since gcc
doesn't permit use of "noreturn" types used in a typecast, resort to
typeof().

No functional change intended.

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

xen/arch/x86/include/asm/current.h

@@ -208,7 +208,7 @@ unsigned long get_stack_dump_bottom (unsigned long sp);
 /* The constraint may only specify non-call-clobbered registers. */
 #define reset_stack_and_call_ind(fn)                                    \
     ({                                                                  \
-        (void)((fn) == (void (*)(void))NULL);                           \
+        (void)((fn) == (typeof(dom_xen->arch.ctxt_switch->tail))NULL);  \
         switch_stack_and_jump(fn, "INDIRECT_CALL %", "b");              \
     })