maple_tree: refactor mas_wr_store_type()

In mas_wr_store_type(), we check if new_end < mt_slots[wr_mas->type].  If
this check fails, we know that ,after this, new_end is >= mt_min_slots. 
Checking this again when we detect a wr_node_store later in the function
is reduntant.  Because this check is part of an OR statement, the
statement will always evaluate to true, therefore we can just get rid of
it.

We also refactor mas_wr_store_type() to return the store type rather than
set it directly as it greatly cleans up the function.

Link: https://lkml.kernel.org/r/20241011214451.7286-2-sidhartha.kumar@oracle.com


Signed-off-by: Sidhartha <sidhartha.kumar@oracle.com>
Suggested-by: Liam Howlett <liam.howlett@oracle.com>
Suggested-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>