recovery: Remove the include of adb.h.

recovery.cpp doesn't have a direct dependency on adb.h (only minadbd
does). 'adb.h' was once needed for DEFAULT_ADB_PORT, until being killed
by commit acb2a2fa.

Test: mmma bootable/recovery
Change-Id: I84f87988d01c3f0c3d1383cc3cffde2e7d5e7aea