staging: rtl8188eu: Compress two statements into one.

This patch removes the use of a variable used only for
returning a value. The following coccinelle script was
used to discover it:

@@
expression ret;
identifier f;
@@

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

It also fixes the checkpatch.pl warning about line being over
80 characters, in the lines where changes were made.

Signed-off-by: Navya Sri Nizamkari <navyasri.tech@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>