tools/liblockdep: explicitly declare lockdep API we call from liblockdep

It seems that newer gcc complains about lack of explicit declaration for some
of the API we use, add it in.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

tools/lib/lockdep/uinclude/linux/lockdep.h

@@ -6,7 +6,7 @@
 #include <string.h>
 #include <limits.h>
 #include <linux/utsname.h>
-
+#include <linux/compiler.h>
 
 #define MAX_LOCK_DEPTH 2000UL
 
@@ -54,5 +54,6 @@ static struct new_utsname *init_utsname(void)
 #define static_obj(x) 1
 
 #define debug_show_all_locks()
+extern void debug_check_no_locks_held(void);
 
 #endif