Remove linux/fiemap.h which is included more than once

Link: https://lore.kernel.org/r/20200819025434.65763-1-wanghai38@huawei.comReported-by: NHulk Robot <hulkci@huawei.com>
Reviewed-by: NRitesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: NWang Hai <wanghai38@huawei.com>
Signed-off-by: NJan Kara <jack@suse.cz>