[PATCH] Revert using -m option to tar in sstate

[Richard Purdie <richard.purdie@linuxfoundation.org>]

In http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=2d89cff42af2bb0049224bfaaebaa2b21966169f
we added a workaround for dealing with lack of time sync between build
machines and their users.

This has turned out to cause problems for people who reply on timestamps
being preserved in sstate output.

Since our autobuilders are all in time sync with ntp, revert the commit.

[YOCTO #8996]

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta/classes/sstate.bbclass b/meta/classes/sstate.bbclass
index 6c3e828..33aa8d7 100644
--- a/meta/classes/sstate.bbclass
+++ b/meta/classes/sstate.bbclass
@@ -703,7 +703,7 @@ sstate_create_package () {
 # Will be run from within SSTATE_INSTDIR.
 #
 sstate_unpack_package () {
-	tar -xmvzf ${SSTATE_PKG}
+	tar -xvzf ${SSTATE_PKG}
 	# Use "! -w ||" to return true for read only files
 	[ ! -w ${SSTATE_PKG} ] || touch --no-dereference ${SSTATE_PKG}
 	[ ! -w ${SSTATE_PKG}.sig ] || [ ! -e ${SSTATE_PKG}.sig ] || touch --no-dereference ${SSTATE_PKG}.sig