staging: rtl8723bs: fix spaces required around unary operator

this patch fixes below issues reported by checkpatch

ERROR: spaces required around that '=' (ctx:WxV)
ERROR: spaces required around that '=' (ctx:WxV)
ERROR: spaces required around that '<' (ctx:VxV)

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>