tracing: Use modern function declaration

We get a lot of harmless warnings about this header file at W=1 level
because of an unusual function declaration:

kernel/trace/trace.h:766:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]

This moves the inline statement where it normally belongs, avoiding the
warning.

Link: http://lkml.kernel.org/r/20170123122521.3389010-1-arnd@arndb.de

Fixes: 4046bf02 ("ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/trace.h

@@ -763,7 +763,7 @@ struct ftrace_hash {
 struct ftrace_func_entry *
 ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
 
-static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
+static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
 {
 	return !hash || !hash->count;
 }