logging: Prior to log initialization, print all logs to syslog.

There can be calls to gf_msg even before caling logging_init().
Currently such messages appear on stderr. In this patch, gf_msg
is changed to log messages to syslog if the logging framework is
not inited.

Change-Id: I8fcf562f9d07b5b6b789fbd9e6f37b354de16b98
BUG: 1103623
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/7948
Reviewed-by: Raghavendra Talur <rtalur@redhat.com>
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>