ocfs2: Always try for maximum bits with new local alloc windows

What we were doing before was to ask for the current window size as the
maximum allocation. This had the effect of limiting the amount of allocation
we could get for the local alloc during times when the window size was
shrunk due to fragmentation. In some cases, that could actually *increase*
fragmentation by artificially limiting the number of bits we can accept. So
while we still want to ask for a minimum number of bits equal to window
size, there is no reason why we should limit the number of bits the local
alloc should accept. Hence always allow the maximum number of local alloc
bits.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>