lttng: Remove procname from callstack requirements

lttng: Remove procname from callstack requirements

The analysis does not need the procname and it adds some overhead in a trace
with a lot of function calls. Though procname makes it prettier, it should not
prevent a user from seeing the callstack of a perfectly workable trace.

Change-Id: I3603b52f8559c40b86193d954ab94d9e65dc9bce
Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Reviewed-on: https://git.eclipse.org/r/87449
Reviewed-by: Hudson CI
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>