SystemInformation: Work around gcc -Wliteral-suffix warning

A single quote in an inline assembly comment is confusing gcc:

 .../SystemInformation.cxx:256:24: warning: invalid suffix on literal;
 C++11 requires a space between literal and identifier [-Wliteral-suffix]
 ; optimiser doesn't know about <<CPUID>>, and so doesn't expect
                  ^

Avoid it by changing "doesn't" to "does not".

Change-Id: Ic4caaeaabfdb99aa486ec09b23d670ec1b125069