KVM: x86: improve the usability of the 'kvm_pio' tracepoint
This patch moves the 'kvm_pio' tracepoint to emulator_pio_in_emulated()
and emulator_pio_out_emulated(), and it adds an argument (a pointer to
the 'pio_data'). A single 8-bit or 16-bit or 32-bit data item is fetched
from 'pio_data' (depending on 'size'), and the value is included in the
trace record ('val'). If 'count' is greater than one, this is indicated
by the string "(...)" in the trace output.