driver/main.c: explicitly include tracepoint.h

this fixes a build problem in the 3.15-rc1 kernel.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver: replace uint32_t with u32

u32 is the proper in-kernel type.

I left alone a public header for now, that will have to change later
after the multi-OS bits are removed from it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>