qdev-properties: Fix (u)intXX parsers

scanf calls must not use PRI constants, they have probably the wrong size and
corrupt memory. We could replace them by SCN ones, but strtol is simpler than
scanf here anyway. While at it, also fix the parsers to reject garbage after
the number ("4096xyz" was accepted before).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Richard Henderson <rth@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
