staging: rtl8712: merge lines and remove unused variable for immediate return

This patch merge two lines in a single line if immediate return is found.
Unused variables in each case were removed manually as they are no longer
needed.

This is done using Coccinelle. Semantic patch used for this is as
follows :
@@
expression ret;
identifier f;
@@

-ret =
+return
     f(...);
-return ret;

Signed-off-by: Tapasweni Pathak <tapaswenipathak@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>