staging: rtl8712: Use completions for signaling

r8712_sitesurvey_cmd() uses a variable to notify r8712_SetFilter() that it
has completed operation. There is no sort of assurance that the variable will
actually change and it could cache the value the first time it is read and
then never update it for the whole loop logic.

Use completion variables because they are better suited for the purpose.

This patch fixes the checkpatch.pl warnings like:
CHECK: Avoid CamelCase: <blnEnableRxFF0Filter>
+   u8 blnEnableRxFF0Filter;

Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Sathish Kumar <skumark1902@gmail.com>
Link: https://lore.kernel.org/r/20220323045515.2513-1-skumark1902@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>