kill: include sys/types.h before checking SYS_pidfd_send_signal

Including sys/types.h must happen before SYS_pidfd_send_signal is checked,
because that header defines variable in normal conditions.  When sys/types.h
does not have SYS_pidfd_send_signal then fallback is defined in config.h
that is included by default, and has therefore worked fine before and after
this change.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

include/pidfd-utils.h

@@ -1,26 +1,28 @@
 #ifndef UTIL_LINUX_PIDFD_UTILS
 #define UTIL_LINUX_PIDFD_UTILS
 
-#if defined(__linux__) && defined(SYS_pidfd_send_signal)
-# include <sys/types.h>
+#if defined(__linux__)
 # include <sys/syscall.h>
+# if defined(SYS_pidfd_send_signal)
+#  include <sys/types.h>
 
-# ifndef HAVE_PIDFD_OPEN
+#  ifndef HAVE_PIDFD_OPEN
 static inline int pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
 				    unsigned int flags)
 {
 	return syscall(SYS_pidfd_send_signal, pidfd, sig, info, flags);
 }
-# endif
+#  endif
 
-# ifndef HAVE_PIDFD_SEND_SIGNAL
+#  ifndef HAVE_PIDFD_SEND_SIGNAL
 static inline int pidfd_open(pid_t pid, unsigned int flags)
 {
 	return syscall(SYS_pidfd_open, pid, flags);
 }
-# endif
+#  endif
 
-# define UL_HAVE_PIDFD 1
+#  define UL_HAVE_PIDFD 1
 
-#endif /* __linux__ && SYS_pidfd_send_signal */
+# endif	/* SYS_pidfd_send_signal */
+#endif /* __linux__ */
 #endif /* UTIL_LINUX_PIDFD_UTILS */