hw: megasas: return -1 when 'megasas_map_sgl' fails

The caller of 'megasas_map_sgl' will only check if the return
is zero or not. If it return 0 it means success, as in the next
patch we will consider 'iov_count=0' is an error, so let's
return -1 to indicate a failure.

Signed-off-by: Li Qiang <liq3ea@163.com>
Message-Id: <20200815141940.44025-2-liq3ea@163.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed