include/linux/smp.h:on_each_cpu(): switch back to a C function

Revert commit c846ef7deb ("include/linux/smp.h:on_each_cpu(): switch
back to a macro").  It turns out that the problematic linux/irqflags.h
include was fixed within ia64 and mn10300.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/smp.h

@@ -11,6 +11,7 @@
 #include <linux/list.h>
 #include <linux/cpumask.h>
 #include <linux/init.h>
+#include <linux/irqflags.h>
 
 extern void cpu_idle(void);
 
@@ -139,14 +140,17 @@ static inline int up_smp_call_function(smp_call_func_t func, void *info)
 }
 #define smp_call_function(func, info, wait) \
 			(up_smp_call_function(func, info))
-#define on_each_cpu(func, info, wait)		\
-	({					\
-		unsigned long __flags;		\
-		local_irq_save(__flags);	\
-		func(info);			\
-		local_irq_restore(__flags);	\
-		0;				\
-	})
+
+static inline int on_each_cpu(smp_call_func_t func, void *info, int wait)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	func(info);
+	local_irq_restore(flags);
+	return 0;
+}
+
 /*
  * Note we still need to test the mask even for UP
  * because we actually can get an empty mask from