This reverts commit cadc4e1a.

Commit cadc4e1a ("sh: Handle calling csum_partial with misaligned
data") causes bad checksum calculations on unaligned data. Reverting
it fixes the problem.

    # Subtest: checksum
    # module: checksum_kunit
    1..5
    # test_csum_fixed_random_inputs: ASSERTION FAILED at lib/checksum_kunit.c:500
    Expected ( u64)result == ( u64)expec, but
        ( u64)result == 53378 (0xd082)
        ( u64)expec == 33488 (0x82d0)
    # test_csum_fixed_random_inputs: pass:0 fail:1 skip:0 total:1
    not ok 1 test_csum_fixed_random_inputs
    # test_csum_all_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:525
    Expected ( u64)result == ( u64)expec, but
        ( u64)result == 65281 (0xff01)
        ( u64)expec == 65280 (0xff00)
    # test_csum_all_carry_inputs: pass:0 fail:1 skip:0 total:1
    not ok 2 test_csum_all_carry_inputs
    # test_csum_no_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:573
    Expected ( u64)result == ( u64)expec, but
        ( u64)result == 65535 (0xffff)
        ( u64)expec == 65534 (0xfffe)
    # test_csum_no_carry_inputs: pass:0 fail:1 skip:0 total:1
    not ok 3 test_csum_no_carry_inputs
    # test_ip_fast_csum: pass:1 fail:0 skip:0 total:1
    ok 4 test_ip_fast_csum
    # test_csum_ipv6_magic: pass:1 fail:0 skip:0 total:1
    ok 5 test_csum_ipv6_magic
 # checksum: pass:2 fail:3 skip:0 total:5
 # Totals: pass:2 fail:3 skip:0 total:5
not ok 22 checksum

Fixes: cadc4e1a ("sh: Handle calling csum_partial with misaligned data")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20240324231804.841099-1-linux@roeck-us.netSigned-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>