[priority] pp_alua correctness fix
[priority] pp_alua correctness fix

Tom Kalus noted path_priority/pp_aula/spc.h misrepresented to spec
regarding the product string lentgh. Credits for the fix too.

Fix acked by Stefan Bader.

gebi/multipath-tools,grzn/multipath-tools-explained,unakatsuo/multipath-tools,vijaychauhan/multipath-tools,grzn/multipath-tools-explained,vijaychauhan/multipath-tools,unakatsuo/multipath-tools,unakatsuo/multipath-tools