maple_tree: clean up inlines for some functions

There are a few functions which were inlined but are somewhat too large to
inline, so remove the inline key word.

There are also several very small functions which are used in critical
code sections which gcc was not inlining, so make this more strict and use
__always_line for these functions.

Link: https://lkml.kernel.org/r/20231101171629.3612299-8-Liam.Howlett@oracle.com


Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>