tools/lib/lockdep: Add missing declaration of 'pr_cont()'

Commit:

681fbec881de ("lockdep: Use consistent printing primitives")

has moved lockdep away from using printk() for printing.

The commit added usage of pr_cont() which wasn't wrapped in the
userspace headers, causing the following warning for the
liblockdep build:

../../../kernel/locking/lockdep.c:3544:2: warning: implicit declaration of function 'pr_cont' [-Wimplicit-function-declaration]

Adding an empty declaration of 'pr_cont' fixes the problem.

Signed-off-by: Mengting Zhang <[e-mail]>
Signed-off-by: Sasha Levin <[e-mail]>
Reviewed-by: Alexander Sverdlin <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

tools/include/linux/lockdep.h

···
 #define printk(...) dprintf(STDOUT_FILENO, __VA_ARGS__)
 #define pr_err(format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define pr_warn pr_err
+#define pr_cont pr_err
 
 #define list_del_rcu list_del