staging: pi433: pi433_if.c codestyle fix

This patch fixes the following checkpatch.pl error:

ERROR: spaces required around that '>=' (ctx:VxV)
#930: FILE: pi433_if.c:930:
+		for (i--; i>=0; i--)

ERROR: spaces required around that '=' (ctx:VxV)
#970: FILE: pi433_if.c:970:
+		for (i=0; i<NUM_DIO; i++)

Signed-off-by: Oliver Graute <oliver.graute@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>