usb: gsi: Fix usage of uninitialized variable

Commit ("8ead8db6 usb: gsi: Add debugfs support
for remote wakeup on each interface") removed the
initialization of the variable "gsi" before it is used
in the macros log_event_dbg and log_event_err. This causes
the access to garbage value leading to unintended results.
Fix this by using the pr_debug and pr_err instead of the
log_event_dbg and log_event_err.

Change-Id: I473c3629b3fc88041863e330aade52761e1dad8e
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>