x86 vdso: fix build locale dependency

Priit Laes discovered that the sed command processing nm output was
sensitive to locale settings.  This was addressed in commit
03994f01e8b72b3d01fd3d09d1cc7c9f421a727c by using [:alnum:] in place of
[a-zA-Z0-9].

But that solution too is locale-dependent and may not always match
the identifiers it needs to.  The better fix is just to run sed et al
with a fixed locale setting in all builds.

Signed-off-by: Roland McGrath <roland@redhat.com>
CC: Priit Laes <plaes@plaes.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/vdso/Makefile

@@ -48,9 +48,11 @@ obj-$(VDSO64-y)			+= vdso-syms.lds
 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
 #
 sed-vdsosym := -e 's/^00*/0/' \
-	-e 's/^\([[:xdigit:]]*\) . \(VDSO[[:alnum:]_]*\)$$/\2 = 0x\1;/p'
+	-e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
 quiet_cmd_vdsosym = VDSOSYM $@
-      cmd_vdsosym = $(NM) $< | sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
+define cmd_vdsosym
+	$(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
+endef
 
 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
 	$(call if_changed,vdsosym)