firmware: arm_sdei: Cleanup on cross call function

This applies cleanup on the cross call functions, no functional
changes are introduced:

   * Wrap the code block of CROSSCALL_INIT inside "do { } while (0)"
     as linux kernel usually does. Otherwise, scripts/checkpatch.pl
     reports warning regarding this.
   * Use smp_call_func_t for @fn argument in sdei_do_cross_call()
     as the function is called on target CPU(s).
   * Remove unnecessary space before @event in sdei_do_cross_call()

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-11-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: Gavin Shan

drivers/firmware/arm_sdei.c

@@ -78,11 +78,15 @@ struct sdei_crosscall_args {
 	int first_error;
 };
 
-#define CROSSCALL_INIT(arg, event)	(arg.event = event, \
-					 arg.first_error = 0, \
-					 atomic_set(&arg.errors, 0))
-
-static inline int sdei_do_cross_call(void *fn, struct sdei_event * event)
+#define CROSSCALL_INIT(arg, event)		\
+	do {					\
+		arg.event = event;		\
+		arg.first_error = 0;		\
+		atomic_set(&arg.errors, 0);	\
+	} while (0)
+
+static inline int sdei_do_cross_call(smp_call_func_t fn,
+				     struct sdei_event *event)
 {
 	struct sdei_crosscall_args arg;