net: wireless: rtlwifi: rtl8192de: phy.c: Cleaning up uninitialized variable

There is a risk that the variables will be used without being initialized.
Have also moved variable to the part of the code where it is used.

This was largely found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: John W. Linville <linville@tuxdriver.com>