All three uses of osl_getFileOSHandle have been removed again

...introduced with a64db11b6ca1c0c99937cd99129758dbbe575ac2 "Add some non-public
API to be used by SvFileStream" and e541105b45d5da8df296883111194e3a0297a2e7
"Use osl API to access files in the SvFileStream code" but subsequently
identified as dead code with ab02fa6552fb098990e74f2787cf02b01c0e532b
"callcatcher: update list," 05a8216d03b5db559e01dd1808f2805df31c970a
"STAR_ENABLE_FILE_LOCKING was a secret," and
1d3483ed279982278b2f9fb1bab63485523e48c5 "Remove some unused code from
unusedcode.easy."

Change-Id: I9c8584890270a87e58b8d8021080ffe54bc97b93