In commit b320ca0 the mask was inadvertently changed from octal 0177 to
hexadecimal 0x177.
Fixes commit b320ca0ffe
Xtest: disallow GenericEvents in XTestSwapFakeInput
Found by Stuart Cassoff
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit bb1711b7fb)