Obsolete earlier packages due to version bump

In order for package managers such as dnf to upgrade cleanly after
the package SONAME bump the obsolete package names must be known.
Update the new packages to correctly obsolete the old ones.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #11230 
Closes #11233

rpm/generic/zfs.spec.in

@@ -165,6 +165,7 @@ This package contains the core ZFS command line utilities.
 %package -n libzpool4
 Summary:        Native ZFS pool library for Linux
 Group:          System Environment/Kernel
+Obsoletes:      libzpool2
 
 %description -n libzpool4
 This package contains the zpool library, which provides support
@@ -176,6 +177,7 @@ for managing zpools
 %package -n libnvpair3
 Summary:        Solaris name-value library for Linux
 Group:          System Environment/Kernel
+Obsoletes:      libnvpair1
 
 %description -n libnvpair3
 This package contains routines for packing and unpacking name-value
@@ -189,6 +191,7 @@ to write self describing data structures on disk.
 %package -n libuutil3
 Summary:        Solaris userland utility library for Linux
 Group:          System Environment/Kernel
+Obsoletes:      libuutil1
 
 %description -n libuutil3
 This library provides a variety of compatibility functions for OpenZFS:
@@ -207,6 +210,7 @@ This library provides a variety of compatibility functions for OpenZFS:
 %package -n libzfs4
 Summary:        Native ZFS filesystem library for Linux
 Group:          System Environment/Kernel
+Obsoletes:      libzfs2
 
 %description -n libzfs4
 This package provides support for managing ZFS filesystems
@@ -225,6 +229,7 @@ Provides:       libzpool4-devel
 Provides:       libnvpair3-devel
 Provides:       libuutil3-devel
 Obsoletes:      zfs-devel
+Obsoletes:      libzfs2-devel
 
 %description -n libzfs4-devel
 This package contains the header files needed for building additional