signal: make has_pending_signals() return bool

has_pending_signals() already behaves like a boolean function.  Let's
actually declare it as such too.

Link: http://lkml.kernel.org/r/20180602103653.18181-11-christian@brauner.io
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Morris <james.morris@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c

@@ -110,7 +110,7 @@ static bool sig_ignored(struct task_struct *t, int sig, bool force)
  * Re-calculate pending state from the set of locally pending
  * signals, globally pending signals, and blocked signals.
  */
-static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked)
+static inline bool has_pending_signals(sigset_t *signal, sigset_t *blocked)
 {
 	unsigned long ready;
 	long i;