Clean-up: consumer: prepend `the_` to global variable

Clean-up: consumer: prepend `the_` to global variable

This avoids name clashes between the global variable and local variables
/ function parameters. This is a step towards enabling -Wshadow.

This also helps readability, in my opinion, as it helps quickly spot
that some code is using a global variable.

Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I20eb47b91e3500bf1aebee17fdb995940cae7a33