e1000: remove unnecessary clearing of SWSM.SWSM_SMBI

e1000: remove unnecessary clearing of SWSM.SWSM_SMBI

remove unnecessary clearing of SWSM.SWSM_SMBI when obtaining the SW
semaphore. This was introduced in 951860634fdb557bbb58e0f99215391bc0c29779
while adding i210 support and should be now resolved by releasing the
semaphore when no longer needed.

Cc: Marcel Ziswiler <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Aneesh Bansal <[email protected]>
Cc: Naveen Burmi <[email protected]>
Cc: Po Liu <[email protected]>
Cc: Bin Meng <[email protected]>
Cc: Alison Wang <[email protected]>
Cc: Reinhard Arlt <[email protected]>
Cc: Shengzhou Liu <[email protected]>
Cc: York Sun <[email protected]>
Signed-off-by: Tim Harvey <[email protected]>
Tested-by: Bin Meng <[email protected]>
Tested-by: Marcel Ziswiler <[email protected]>