qf: SC1083 - Fix another shellcheck complain.

^-- SC1083: This { is literal. Check expression (missing ;/\n?) or quote it.^

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Jani Nikula <jani.nikula@intel.com>

qf

@@ -403,9 +403,9 @@ function qf_pull
 	cd patches
 
 	if [[ $1 == "--rebase" ]] ; then
-		git rebase @{upstream}
+		git rebase "@{upstream}"
 	else
-		git merge @{upstream}
+		git merge "@{upstream}"
 	fi
 
 	qf co