sf: stmicro: dont send 4 bytes when reading status register

I can't find anywhere in the datasheet that says the status register needs
3 dummy bytes sent to it before being able to read back the first real
result.  Tests on a Blackfin board show that after writing the opcode, the
status register starts coming back immediately.  So only write out the
read status register opcode before polling the result.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Jason McMullan <mcmullan@netapp.com>
CC: TsiChung Liew <Tsi-Chung.Liew@freescale.com>