usb: host: ehci-sched: remove unnecessary braces

This patch removes unnecessary braces in single statement blocks at the
same time as replaces the if statement with a ternary conditional.

Tested by compilation only.
Caught by checkpatch.

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>