octeontx2-af: fix error code in is_valid_offset()

The is_valid_offset() function returns success/true if the call to
validate_and_get_cpt_blkaddr() fails.

Fixes: ecad2ce8 ("octeontx2-af: cn10k: Add mailbox to configure reassembly timeout")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YpXDrTPb8qV01JSP@kiliSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/marvell/octeontx2/af/rvu_cpt.c

@@ -579,7 +579,7 @@ static bool is_valid_offset(struct rvu *rvu, struct cpt_rd_wr_reg_msg *req)
 
 	blkaddr = validate_and_get_cpt_blkaddr(req->blkaddr);
 	if (blkaddr < 0)
-		return blkaddr;
+		return false;
 
 	/* Registers that can be accessed from PF/VF */
 	if ((offset & 0xFF000) ==  CPT_AF_LFX_CTL(0) ||