VTN Coordinator UT is unable to be built on Fedora 21 (x86_64).

I observed the following error when I built VTN Coordinator UT on Fedora 21 (x86_64).

sub_flock.c: In function 'main':
sub_flock.c:259:3: error: 'contents' may be used uninitialized in this function [-Werror=maybe-uninitialized]
free(contents);
^
sub_flock.c:190:9: note: 'contents' was declared here
char *contents;
^

Although this test never uses uninitialized variable, this error should be fixed.