[PATCH] kbuild: Eliminate build error when KALLSYMS not defined

[Sam Ravnborg <sam@ravnborg.org>]

Hi Linus, please apply before -final. It eliminates annoying output when
we do not compile with CONFIG_KALLSYMS enabled.

From: Mark Rustad <MRustad@mac.com>

The following build error happens with 2.6.14-rc4
when CONFIG_KALLSYMS is not defined. The error
message in a fragment of the output was:

  CC      arch/i386/lib/usercopy.o
  AR      arch/i386/lib/lib.a
/bin/sh: line 1: +@: command not found
make[3]: warning: jobserver unavailable: using -j1.  Add `+' to parent make rule.
  CHK     include/linux/compile.h

The following patch fixes it.

Signed-off-by: Mark Rustad <mrustad@mac.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
---

diff --git a/Makefile b/Makefile
index 4e0d7c6..a3ffa20 100644
--- a/Makefile
+++ b/Makefile
@@ -660,8 +660,10 @@ quiet_cmd_sysmap = SYSMAP 
 # Link of vmlinux
 # If CONFIG_KALLSYMS is set .version is already updated
 # Generate System.map and verify that the content is consistent
-
+# Use + in front of the vmlinux_version rule to silent warning with make -j2
+# First command is ':' to allow us to use + in front of the rule
 define rule_vmlinux__
+	:
 	$(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))
 
 	$(call cmd,vmlinux__)