Added pritnk to written value from userspace

Change-Id: I1286b21cb4e6c3c86e7357311b28078aa70afc61
Added -Wall CFLAGS to compile test_intn

Change-Id: I7d2062fba4f1abdd445154adbaf08678a249dcf9
Added command line parsing to test_intn

Change-Id: Ic9bd7b75132c38746ee77962cc8be38a4573e26c
Fixed test_intn

Removed read_devintn fucntion. The test concept was wrong, because the thread
was reading and the thread with wrtie_devintn was reading and just afterwairds
writing again, performing 2 I/O operations. The write_devintn was renamed to
inc_devintn and now every thread increments by one the intn value.

Change-Id: I3e6434a7562c6e7328a2cb3fbc4f8e61e738469a