[PATCH lttng-ust] Fix: Initialize fd field of struct lttng_ust_elf to -1 at allocation

[Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>]

In rare cases when the executable cannot be open, using a default value
of zero lead to invalid close call and fd tracker removal.

fixes #1171

Reported-by: Stefan Palade <stefan.palade@windriver.com>
Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
---
 liblttng-ust/lttng-ust-elf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/liblttng-ust/lttng-ust-elf.c b/liblttng-ust/lttng-ust-elf.c
index c073e7a5..3d6a9379 100644
--- a/liblttng-ust/lttng-ust-elf.c
+++ b/liblttng-ust/lttng-ust-elf.c
@@ -250,6 +250,8 @@ struct lttng_ust_elf *lttng_ust_elf_create(const char *path)
 		goto error;
 	}
 
+	/* Initialize fd field to -1. 0 is a valid fd number */
+	elf->fd = -1;
 
 	elf->path = strdup(path);
 	if (!elf->path) {
-- 
2.17.1