ext4: remove unnecessary drop path references in mext_check_coverage()

According to Jan Kara's suggestion:
"The use in mext_check_coverage() can be actually removed
- get_ext_path() -> ext4_find_extent() takes care of dropping the references."
So remove unnecessary call ext4_ext_drop_refs() in mext_check_coverage().
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220924021211.3831551-2-yebin10@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/move_extent.c

@@ -103,7 +103,6 @@ mext_check_coverage(struct inode *inode, ext4_lblk_t from, ext4_lblk_t count,
 		if (unwritten != ext4_ext_is_unwritten(ext))
 			goto out;
 		from += ext4_ext_get_actual_len(ext);
-		ext4_ext_drop_refs(path);
 	}
 	ret = 1;
 out: