The sufficient number of fragments needed for MTU 1500 and 8b compression is 6. However, XRAN_MAX_FRAGMENT must be incremented by one (6+1 = 7). In the MR https://gitlab.eurecom.fr/oai/openairinterface5g/-/merge_requests/3394, XRAN_MAX_FRAGMENT was increased to 6, but the Tx data was actually copied 5 times, and unfortunately I haven't tested end-to-end back then. This commit was successfully tested with Liteon FR1.