staging: xroeframer: rename "lp" to "xroe_lp"

There are two global variables with the same name "lp". This will result
the link error as below:

aarch64-linux-gnu-ld: drivers/staging/xroeframer/xroe_framer.o:(.bss+0x0): multiple definition of `lp'; drivers/net/ethernet/xilinx/xilinx_tsn_switch.o:(.bss+0x80): first defined here

Change "lp" to "xroe_lp" in xroe_framer.c to avoid this error.

Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>