make: increase maximum template recursion depth

With clang on OSX spirit blows up without this.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
mon: check for sys/vfs.h existence

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
rados_sync: remove unused private variable

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
rados_sync: fix mismatched tag warning

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
librbd: rename howmany to avoid conflict

A howmany macro exists on some platforms in standard headers, but there
really isn't any sort of standard that I've found. We just avoid the
conflict entirely this way.

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
TrackedOp: remove unused private variable

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
librbd: remove unused private variable

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
Merge pull request #918 from ceph/port/misc

Misc portability patches

Reviewed-by: Sage Weil <sage@inktank.com>