--with-babeltrace generates many FAILs

Hi Yao,

since 65c749e7c049f9bf944c5fbe9e727b7a8b4ccc7c (Fix build/17104) babeltrace
got enabled for me but now I get many new FAILs in testsuites, such as for
gdb.trace/actions.exp:
	(gdb) target ctf .../gdb/testsuite/gdb.trace/actions.ctf
	[error] Invalid CTF stream: content size is smaller than packet headers.
	[error] Stream index creation error.
	[error] Open file stream error.
	[warning] [Context] Cannot open_trace of format ctf at path .../gdb/testsuite/gdb.trace/actions.ctf.
	Unable to use libbabeltrace on directory ".../gdb/testsuite/gdb.trace/actions.ctf"
	(gdb) PASS: gdb.trace/actions.exp: change to ctf target
	info tracepoints 1
	No tracepoint matching '1'.
	(gdb) info tracepoints 2
	No tracepoint matching '2'.
	(gdb) info tracepoints 3
	No tracepoint matching '3'.
	(gdb) FAIL: gdb.trace/actions.exp: ctf: tracepoint on gdb_c_test
	FAIL: gdb.trace/actions.exp: ctf: tracepoint on gdb_asm_test
	FAIL: gdb.trace/actions.exp: ctf: tracepoint on gdb_recursion_test 0
	testcase ./gdb.trace/actions.exp completed in 2 seconds

Tested with libbabeltrace-1.2.1-2.fc21.x86_64.
Tested on Fedora 21pre x86_64 (but it looks the same on Fedora 20 x86_64).

I sure can start debugging it but only if you have some idea.


Jan