Alert properly when we have stale mounts left after interupting a tinybsd build.  If we do not do this, we can accidentally remove critical files from directories like /lib (if mounted).
Alert properly when we have stale mounts left after interupting
a tinybsd build.  If we do not do this, we can accidentally remove
critical files from directories like /lib (if mounted).

PR:		misc/121763
Submitted by:	Richard Arends < richard at unixguru dot nl >
MFC after:	3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase