fanotify21: fix compile complain

fanotify21.c:42:1: warning: useless storage class specifier in empty declaration
   42 | };
      | ^

Fixes: 23bf384 ("fanotify: Fix various checkparse warnings")
Closes: #977

Reviewed-by: Petr Vorel <[email protected]>
Reviewed-by: Cyril Hrubis <[email protected]>
Signed-off-by: Rong Tao <[email protected]>

Author: Rtoax

testcases/kernel/syscalls/fanotify/fanotify21.c

@@ -33,7 +33,7 @@
 #define MOUNT_PATH	"fs_mnt"
 #define TEST_FILE	MOUNT_PATH "/testfile"
 
-static struct pidfd_fdinfo_t {
+struct pidfd_fdinfo_t {
 	int pos;
 	int flags;
 	int mnt_id;