o In em_if_update_admin_status():

• Don't bother calling if_setbaudrate(9) as iflib_link_state_change(9) takes care of that,
• correctly check for E1000_CTRL_EXT_LINK_MODE_GMII in E1000_CTRL_EXT [1],
• properly convert the uint16_t link_speed to a uint64_t baudrate by using IF_Mbps() which contains an appropriate cast [2],
• remove the duplicate link down announcement when bootverbose isn't zero and bring the remaining one in line with the other link state messages.

o Remove a dead store to rid in em_if_msix_intr_assign(). [3]
o Or in the DMA coalescing Rx threshold so the other bits set in E1000_DMACR

remain intact as intended in igb_init_dmac(). [4]

Reported by: Coverity
CID: 1378464 [1], 1368765 [2], 1381681 [3], 1304929 [4]