staging: rtl8192e: remove set but not used variable 'frag'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c: In function _rtl92e_process_phyinfo:
drivers/staging/rtl8192e/rtl8192e/r8192E_dev.c:1689:15: warning: variable frag set but not used [-Wunused-but-set-variable]

It is introduced by commit 3d461c91 ("rtl8192e:
Split into two directories"), but never used, so remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1574063901-87429-1-git-send-email-zhengbin13@huawei.com


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