Makefile: Fix install.* prerequisites
Makefile: Fix install.* prerequisites

Without this change, hitting these targets directly will fail.  For
example:

  $ make clean
  $ make MANDIR=/tmp install.man
  install  -d -m 755 /tmp/man5
  install  -d -m 755 /tmp/man8
  install  -m 644 docs/crio.conf.5 -t /tmp/man5
  install: cannot stat 'docs/crio.conf.5': No such file or directory
  make: *** [Makefile:150: install.man] Error 1

Signed-off-by: W. Trevor King <f75897670c17327c42ab201733fb8a81ff9f4c34@tremily.us>

mikebrow/cri-o,nalind/cri-o,jwhonce/ocid,kubernetes-incubator/ocid,rhatdan/cri-o,mikebrow/cri-o,mikebrow/cri-o,vbatts/cri-o,rhatdan/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/ocid,vbatts/cri-o,rhatdan/cri-o,kubernetes-incubator/cri-o,nalind/cri-o,nalind/cri-o,jwhonce/ocid,jwhonce/ocid,kubernetes-incubator/ocid,kubernetes-incubator/cri-o,mikebrow/cri-o,kubernetes-incubator/cri-o,vbatts/cri-o,rhatdan/cri-o,vbatts/cri-o