qtaguid: test: fix issue with buffer overflow

Fixed the bug that test program cannot read socket addr directly from
ctrl file, changed the implementation of read ctrl file to prevent
possible fails when the ctrl file size is greater then the read buffer
size.

Test: manually tested on angler device. build and sync this module into
device and run adb shell ./data/nativetest64/socketTag/socketTag

Change-Id: I68a8513814a97d9417e13ad320a079510591d3a2
1 file changed