Crush: Ensuring at most num-rep osds are selected

Crush: Ensuring at most num-rep osds are selected

Crush temporary buffers are allocated as per replica size configured
by the user.When there are more final osds (to be selected as per
rule) than the replicas, buffer overlaps and it causes crash.Now, it
ensures that at most num-rep osds are selected even if more number of
osds are allowed by indep rule. The fix for firstn rules is already
merged as part of bug #9492. Required test files are added.

Fixes: #9492
Signed-off-by: Johnu George johnugeo@cisco.com
(cherry picked from commit 234b066ba04976783d15ff2abc3e81b6cc06fb10)