remove pthread mutex locks as they are not needed

src/cmdu.c

src/cmdu.h

src/cmdu_input.c

src/cmdu_output.c

src/cmdufrag.c

src/cmdufrag.h

src/extensions/map/tests/mapclient.c

src/extensions/map/tests/mapclient1.c

src/extensions/map/tests/mapclient2.c

src/i1905_al.c

src/midgen.c

src/neigh.c

src/neigh.h