Killing `adb` server(aka daemon) prevents seeing groups of these messages
on dmesg every second:
[ 1460.763742] pcieport 0000:00:1c.4: restoring config space at offset 0x2c (was 0x0, writing 0x0)
[ 1460.763748] pcieport 0000:00:1c.4: restoring config space at offset 0x28 (was 0x0, writing 0x0)
[ 1460.763752] pcieport 0000:00:1c.4: restoring config space at offset 0x24 (was 0x1fff1, writing 0x1fff1)
[ 1460.763813] pcieport 0000:00:1c.4: PME# disabled
[ 1460.763920] xhci_hcd 0000:03:00.0: PME# disabled
[ 1460.763928] xhci_hcd 0000:03:00.0: enabling bus mastering
[ 1460.770239] xhci_hcd 0000:03:00.0: PME# enabled
[ 1460.770377] xhci_hcd 0000:03:00.0: PME# disabled
[ 1460.770383] xhci_hcd 0000:03:00.0: enabling bus mastering
[ 1460.884813] xhci_hcd 0000:03:00.0: PME# enabled
[ 1460.884925] pcieport 0000:00:1c.4: PME# enabled

safety bonus: we only kill it if we started it.

no need to futureproof an 'if' case (causing confusion) for when the "=="
would be changed to an "-eq" and $we_started_adb_daemon would be empty.