Fix warning due non-standard inline declaration in 4ed8f0913b

Reported-by: Alexander Lakhin, Tom Lane
Author: Pavel Borisov
Discussion: https://postgr.es/m/55d8800f-4a80-5256-1e84-246fbe79acd0@gmail.com

src/backend/access/transam/slru.c

@@ -60,7 +60,7 @@
 #include "storage/fd.h"
 #include "storage/shmem.h"
 
-static int	inline
+static inline int
 SlruFileName(SlruCtl ctl, char *path, int64 segno)
 {
 	if (ctl->long_segment_names)