Convert a missed u_char cpu -> int cpu.

This was caught by a gcc build.

Reported by:	luigi
Sponsored by:	Norse Corp, Inc.
ARC4RANDOM: using _rs_random_u32 call instead.
Provide vfs suspension support only for filesystems which need it.

Need is expressed by providing vfs_susp_clean function in vfsops.

Differential Revision:	D952
Reviewed by:	kib (previous version)
MFC after:	2 weeks
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/hardening
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/ptrace
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/log
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/chacha
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/pie
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/hardening' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/ptrace' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/log' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/userlandenhanced' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/pie' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/chacha' into hardened/current/unstable