Fix a Clang 'sometimes-uninitialized' warning in aug_escape_name()
Fix a Clang 'sometimes-uninitialized' warning in aug_escape_name()

If `in' or `out' is NULL, then the uninitialized value of `result' was
returned.

ptoscano/augeas,lutter/augeas,kunkku/augeas,kunkku/augeas,hercules-team/augeas,hercules-team/augeas,pevalme/augeas,lutter/augeas,pevalme/augeas,lutter/augeas,ptoscano/augeas,kunkku/augeas,mchf/augeas,ptoscano/augeas,dafugg/augeas,dafugg/augeas,pevalme/augeas,mlichvar/augeas,mchf/augeas,mlichvar/augeas,dafugg/augeas,mlichvar/augeas,manandbytes/augeas,manandbytes/augeas