Continue reshape after assembling array

Continue reshape after assembling array

assemble_container_content() cannot close mdfd handle, as it could be
required by reshape continuation.
mdfd handle is closed outside this function, when it is not longer
necessary.
Call to Grow_continue is added for reshape continuation after
assembly.

In the nearest future, simple condition:
    if (content->reshape_active)
before Grow_continue() call will be replaced by check function
for support container operation /reshape/.

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>