HID: pidff: Make sure to fetch pool before checking SIMULTANEOUS_MAX

As noted by Anssi some 20 years ago, pool report is sometimes messed up.
This worked fine on many devices but casued oops on VRS DirectForce PRO.

Here, we're making sure pool report is refetched before trying to access
any of it's fields. While loop was replaced with a for loop + exit
conditions were moved aroud to decrease the possibility of creating an
infinite loop scenario.

Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>