Fix: flt.lttng-utils.debug-info: note name memcmp() overflow

Fix: flt.lttng-utils.debug-info: note name memcmp() overflow

Issue
=====
If the note section that we are currently parsing has a name longer
than the "GNU" string, the `memcmp()` call will read garbage after the
"GNU" string.

I witnessed this when the component was parsing a note section named
"stapsdt".

Solution
========
Make the section name length comparison explicit.

Drawbacks
=========
None.

Reported-by: Address Sanitizer - Global buffer overflow
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I515f8c883ddbc1884045e86aecef700ee2111959
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1322
Tested-by: jenkins
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>