staging:rtl8192u: Rename InactTimer > inact_timer - Style

Rename the struct TS_COMMON_INFO member InactTimer to inact_timer.
This change clears the checkpatch issue with CamelCase naming. The change
should not have any impact on runtime execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>