Fix trace-collection.h: No such file or directory that build code with libbabeltrace

Fix trace-collection.h: No such file or directory that build code with libbabeltrace

After I install the babeltrace and try to build a code, I got this:
gcc -Wall  -g 1.c -lbabeltrace -lbabeltrace-ctf
In file included from 1.c:11:0:
/usr/local/include/babeltrace/babeltrace.h:23:41: fatal error:
babeltrace/trace-collection.h: No such file or directory
compilation terminated.

I check the code, looks most of function of trace-collection.h is
covered by context.h.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>