dccp: fix return value for sequence-invalid packets
dccp: fix return value for sequence-invalid packets

Currently dccp_check_seqno returns 0 (indicating a valid packet) if the
acknowledgment number is out of bounds and the sync that RFC 4340 mandates at
this point is currently being rate-limited. This function should return -1,
indicating an invalid packet.

Signed-off-by: Samuel Jero <ccd1762dfd90f6bd9883c4c64932053b6ab56033@ohio.edu>
Acked-by: Gerrit Renker <3b97070d46ccd66422a8e7b83e6967ed84780538@erg.abdn.ac.uk>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs