KVM: x86 emulator: Use DstAcc for 'and'

For instruction 'and al,imm' we use DstAcc instead of doing
the emulation directly into the instruction's opcode.

Signed-off-by: Guillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>