ceph.spec.in: Fix unversioned Obsoletes: rpmbuild warning

Fix the following warning while building source rpm with `rpmbuild`:

warning: line 1187: It's not recommended to have
  unversioned Obsoletes: Obsoletes: ceph-libcephfs

Signed-off-by: Anoop C S <[email protected]>

Author: anoopcs9

ceph.spec.in

@@ -1184,7 +1184,7 @@ Group:		System/Libraries
 Obsoletes:	libcephfs1 < %{_epoch_prefix}%{version}-%{release}
 %if 0%{?rhel} || 0%{?fedora} || 0%{?openEuler}
 Obsoletes:	ceph-libs < %{_epoch_prefix}%{version}-%{release}
-Obsoletes:	ceph-libcephfs
+Obsoletes:	ceph-libcephfs < %{_epoch_prefix}%{version}-%{release}
 %endif
 %description -n libcephfs2
 Ceph is a distributed network file system designed to provide excellent