target: go through normal processing for all zero-length commands
target: go through normal processing for all zero-length commands

Yay, all users of transport_kmap_data_sg now check for a zero-length
request and/or a too-small parameter list length.  We can thus go through
the normal emulation path even for such commands.

This means that out-of-bounds reads and writes are now reported correctly
even if they transfer 0 blocks.  Other errors are also reported correctly.

Testcase: sg_raw /dev/sdb 28 00 80 00 00 00 00 00 00 00
    should fail with ILLEGAL REQUEST / LBA OUT OF RANGE sense
    does not fail without the patch
    (still wrong with the patch, but better: the ASC is INVALID FIELD IN CDB)

Signed-off-by: Paolo Bonzini <69d3ebcf5ee4e7f05a50dc23cd96655b730804b4@redhat.com>
Signed-off-by: Nicholas Bellinger <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs