Correct the output of the "info mem" and "info tlb" monitor commands to
correctly show canonical addresses.

In 48-bit addressing mode, the upper 16 bits of linear addresses are
equal to bit 47. In 57-bit addressing mode (LA57), the upper 7 bits of
linear addresses are equal to bit 56.

Signed-off-by: Doug Gale <doug16k@gmail.com>
Message-Id: <20180617084025.29198-1-doug16k@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>