Missing header in freespace.c when building for Android

Building tor 0.3.5.3-alpha for Android fails with the following error:

src/lib/fs/freespace.c: In function 'tor_get_avail_disk_space':
src/lib/fs/freespace.c:59:3: error: 'errno' undeclared (first use in this function)
   errno = ENOSYS;
   ^
src/lib/fs/freespace.c:59:3: note: each undeclared identifier is reported only once for each function it appears in
src/lib/fs/freespace.c:59:11: error: 'ENOSYS' undeclared (first use in this function)
   errno = ENOSYS;
           ^
Makefile:9088: recipe for target 'src/lib/fs/freespace.o' failed

On Android <errno.h> should be included in the header.

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Username: goapunk