bnxt_en: Prevent TX timeout with a very small TX ring

If xmit_more condition is true, the driver may set the
TX_BD_FLAGS_NO_CMPL flag.  If after this packet, the TX ring can no
longer hold a packet with maximum fragments, we will stop the TX
queue.  When this happens, we must clear the TX_BD_FLAGS_NO_CMPL flag
on the last packet or there will be no completion and cause TX
timeout.

Fixes: c1056a59

 ("bnxt_en: Optimize xmit_more TX path")
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Reviewed-by: Hongguang Gao <hongguang.gao@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/20231212005122.2401-5-michael.chan@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>