staging: r8188eu: core: Remove rtw_mfree_all_stainfo()

Remove rtw_mfree_all_stainfo() and the only line of code that calls
it. This function simply takes a spinlock and iterates over a list
with no purpose. That iteration has no side effects.

Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210802005517.12815-1-fmdefrancesco@gmail.com


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