selinux: use "grep -E" instead of "egrep"

The latest version of grep claims that egrep is now obsolete so the build
now contains warnings that look like:
	egrep: warning: egrep is obsolescent; using grep -E
fix this by using "grep -E" instead.

Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: selinux@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[PM: tweak to remove vdso reference, cleanup subj line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

scripts/selinux/install_policy.sh

@@ -78,7 +78,7 @@ cd /etc/selinux/dummy/contexts/files
 $SF -F file_contexts /
 
 mounts=`cat /proc/$$/mounts | \
-	egrep "ext[234]|jfs|xfs|reiserfs|jffs2|gfs2|btrfs|f2fs|ocfs2" | \
+	grep -E "ext[234]|jfs|xfs|reiserfs|jffs2|gfs2|btrfs|f2fs|ocfs2" | \
 	awk '{ print $2 '}`
 $SF -F file_contexts $mounts