common/fiemap.cc: fix realloc memory leak

Fix error from cppcheck:

[src/common/fiemap.cc:73]: (error) Common realloc mistake: 'fiemap'
  nulled but not freed upon failure

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit f26f1470e7af36fa1eb8dc59c8a7c62c3c3a22ba)
os/FileStore.cc: fix realloc memory leak in error case

Fix error from cppcheck:

[src/os/FileStore.cc:512]: (error) Common realloc mistake: 'fiemap'
  nulled but not freed upon failure

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit c92a0f552587a232f66620170660d6b2ab6fb3a5)
rgw/rgw_xml.cc: fix realloc memory leak in error case

Fix error from cppcheck:

[src/rgw/rgw_xml.cc:212]: (error) Common realloc mistake: 'buf'
  nulled but not freed upon failure

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit d48cc789ea075ba2745754035640ada4131b2119)
SyntheticClient.cc: fix some memory leaks in the error handling

Fix some memory leaks in case of error handling due to failed
client->open() calls.

Error from cppcheck was:
[src/client/SyntheticClient.cc:1980]: (error) Memory leak: buf
[src/client/SyntheticClient.cc:2040]: (error) Memory leak: buf
[src/client/SyntheticClient.cc:2090]: (error) Memory leak: buf
(cherry picked from commit f0ba80756d1c3c313014ad7be18191981fb545be)
rgw/rgw_rest.cc: fix 4K memory leak

Fix 4K memory leak in case RGWClientIO::read() fails in
read_all_chunked_input().

Error from cppcheck was:
Checking src/rgw/rgw_rest.cc...
[src/rgw/rgw_rest.cc:688]: (error) Memory leak: data

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
(cherry picked from commit 89df090e04ef9fc5aae29122df106b0347786fab)
Merge pull request #64 from dalgaaf/wip-bobtail-memleaks

cherry-pick some memleak fixes from master to bobtail