Staging: wlan-ng: Remove multiple assignments

Remove multiple assignments by factorizing them.
Made a coccinelle script to match cases:
@@
identifier a,b;
constant c;
@@
-a=b=c;
+a=c;
+b=c;

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>