Crash in driGetConfigAttribIndex()

[David Miller]

For values that are GLboolean, this function does the wrong thing.
It's trying to dereference a pointer to a GLboolean as an
"unsigned int *" which won't work and in fact will get a SIGBUS
on platforms like sparc that require proper data alignment.

In my case the X server crashes trying to fetch a
__DRI_ATTRIB_FLOAT_MODE value here.

Perhaps these members simply need special handling in the switch
statement.