ext4: move setting of trimmed bit into ext4_try_to_trim_range()

Currently we set the group's trimmed bit in ext4_trim_all_free() based
on return value of ext4_try_to_trim_range(). However when we will want
to abort trimming because of suspend attempt, we want to return success
from ext4_try_to_trim_range() but not set the trimmed bit. Instead
implementing awkward propagation of this information, just move setting
of trimmed bit into ext4_try_to_trim_range() when the whole group is
trimmed.

Cc: stable@kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230913150504.9054-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>